Welcome to the documentation for the Helio project, a free lightweight music sequencer that runs on all major desktop and mobile operating systems.

Helio was designed to save me time struggling with the MIDI editor, so I could focus more on musical ideas. In this documentation, I’ll also try to save time by keeping it as short and simple as possible.

If you notice that something important is missing, which I’m pretty sure it is, send me an angry email, or file a PR on Github.

Some generated content will be missing if you read this page in the project’s repository, see the full rendered version at

How to read this

If you’re starting out with Helio, just keep reading the Getting Started page to learn the basic concepts of UI navigation, setting up instruments, creating a project, editing and arranging it, and saving your work in the version control.

Otherwise, you might find the editing tips useful: the majority of the nifty tools and hacks are described there.

If you’ve already tinkered with Helio for a while, you’ll probably only need the hotkeys section.


Helio is released as a single portable executable file, where possible, but installers are also available for some systems. In both flavors it has a small disk footprint (less than 10 Mb) and should run on most available hardware and platform versions.

Portable vs installer

Installers are provided for Windows and Debian-based Linux distributions. The installer version is only required if you want the desktop shortcut and the uninstall tool.

To use the portable version, simply download the compressed archive and unzip it to a folder of your choice.

32 or 64 bits

The only practical difference between the two is that the 64-bit version can only host 64-bit plugins, and the 32-bit version can only host 32-bit plugins.

At the moment of writing this, Helio does not support plugin sandboxing or hosting both 32-bit and 64-bit plugins at the same time.

Master build or development build

The master builds are the most recent stable versions. You can keep up to date with the latest changes through the release notes. Install the development build if you want to preview the latest features or verify bug fixes.

Used directories

Helio keeps all files in two directories: one for project files, and another for configuration files.

Note that the installer-based versions don’t remove any of these when uninstalling the app. If you want to completely remove Helio from the system, you should delete them manually.

The configuration directory

All configuration files are created on the first start under the user application data directory. The directory location is platform-dependent:

  • Windows: %APPDATA%\Helio
  • macOS: ~/Library/Application Support/Helio
  • Linux: ~/.config/Helio


This file basically contains all the settings, so deleting or renaming it will cause the app to run as if it were the first time. The settings are intended to be human-readable and are stored in XML format.

translations.helio and maybe others

If the update checks are enabled, some additional resources are updated in the runtime. At the moment of writing, only translations are being updated in this manner.

The projects directory

The project files are saved to the user’s default documents folder in the Helio subfolder. This directory’s location is also platform-dependent:

  • Windows: %HOMEPATH%\Helio (for example, “c:\Users\Peter\Documents\Helio")
  • macOS: ~/Documents/Helio
  • Linux: ~/Documents/Helio

Building from source

Building the app from source will require a C++14 compiler, e.g. GCC 5.0 or Clang 3.4 on Linux, Visual Studio 2015 on Windows, or Xcode 9.2 on macOS.

Minimum deployment targets are:

  • Windows: Windows Vista
  • macOS: macOS 10.7
  • Linux: mainstream distributions

Basic build instructions

  • Clone with submodules: git clone --recursive
  • Install dependencies:
    • On Windows, get ASIO SDK (which can’t be redistributed in this project due to licensing restrictions, but you may use ThirdParty/ASIO/get_asio_sdk.ps1 powershell script to download and extract the SDK source).
    • On Linux, you’ll need to have the following packages installed: libfreetype6-dev libx11-dev libxinerama-dev libxrandr-dev libxcursor-dev libxcomposite-dev mesa-common-dev freeglut3-dev libcurl4-openssl-dev libasound2-dev libjack-dev libc++-dev; the makefile assumes you’ve set up either export CONFIG=Debug, export CONFIG=Release32 or export CONFIG=Release64 before you make.
  • Pick the right project for your OS from the Projects directory and build.


  • Be sure to clone the repository with recursive mode enabled so that the ThirdParty folder is pre-populated with the neccecary files. Alternatively, add them yourself by going to their respecive repositories.
  • If you experience build errors, make sure you have ALL required dependencies installed in your system.
  • If you experience the error: [‘exchange’ is not a member of ‘std’], add [#include ] to JUCE/modules/juce_core/system/juce_StandardHeader.h in the appropriate place. This is an issue pending resolution with the JUCE library, and is probably not a problem with your compiler.

Release notes

Helio features and updates

All notable changes to this project will be documented in this file. For more detailed info, please see the git log.

Version 3.11

  • Added built-in SoundFont player instrument
  • Migrated to JUCE 7 and enabled experimental support for hosting LV2 plugins
  • Microtonality: added built-in 26-edo temperament, fixed Alt + Up/Down transposition hotkeys for microtonal layouts, fixed Pianoteq keyboard mapping presets to match A440 on default settings
  • Piano roll: added staccato and legato commands (Alt + S and Alt + L hotkeys), clicking a single note makes that note’s velocity and length the default, holding Alt disables snapping to barlines
  • Pattern roll: improved solo mode indication (implicitly muted tracks are dimmed)
  • Tempo dialog: adjusting the tempo with mouse wheel
  • Render dialog: preview the waveform while rendering
  • Fixed regressions in computing time codes and in the audio rendering code

Version 3.10

  • Added built-in metronome, toggled by Control + M hotkey, each time signature now has its own editable metronome scheme
  • Added an option to select the MIDI output device
  • Added an option to scale the UI x1.5 or x2
  • Made the update checks optional
  • Updated the app icon
  • Fixed renaming or recoloring multiple tracks in the pattern roll
  • Minor fixes: double click on a tempo track opens “set one tempo” dialog, fixed some grid arrangement glitches and inaccurate time signature alignment, fixed zooming out in large projects, fixed inactive notes blocking double-clicks on the roll

Version 3.9

  • Added per-track time signatures: hotkey Alt + F2 to add a time signature anchored to track’s position
  • Made retrograde hotkey work in the pattern roll, re-ordering all selected clips backwards for each row
  • Implemented auto-fitting the roll view range by zooming it out until it “clicks”
  • Added support for nonoctave tunings (only affect the built-in instrument at the moment)
  • Minor tweaks: more conventional right click menu behavior on multiple selection, improved aligning the dragged clips in the pattern roll, long-overdue UI fixes for smaller phone screens

Version 3.8

  • Added in-scale transposition commands, hotkeys Alt + Up and Alt + Down
  • Implemented recording MIDI from a 12-tone keyboard in any temperament
  • Improved the pen tool: delete notes and clips with right mouse button
  • Improved the knife tool: merge two clips into one or join notes with right mouse button (long tap on mobile platforms)
  • Added “save preset” button in the key signature editor
  • Mini-map improvements: draw a zoom region with left mouse button and pan the stretched mini-map with right mouse button
  • Minor tweaks: allowed “natural” scrolling in the rolls on macOS, improved file choosers for mobile platforms, updated 19-edo settings, re-ordered the edit modes a bit

Version 3.7

  • Made the playback loop markers draggable
  • Added 19-edo to built-in temperaments
  • Added keyboard mapping presets menu (with some built-in multi-channel mappings for Pianoteq), allowing to save your own presets
  • Lasso improvements: added a cool selection range dashed indicator in the roll headers and fixed selection behavior when deselecting items with Alt
  • Mouse wheel control improvements: added support for mice with dual-axis wheels and added a separate “vertical zooming by default” UI option
  • Fixed missing note-offs when editing, which broke some VST3 plugins
  • Facelifted the default color schemes
  • Minor convenience tweaks: global zooming with Alt modifier key, toggling mini-map mode with a click at scroller’s free area, transposing by perfect fifth or equivalent with Control + Shift + Up/Down hotkeys

Version 3.6

  • Fixed VST3 plugins showing black screen and made minor improvements in instrument management
  • Fixed loading the invalid audio settings (which caused issues when using JACK)
  • Fixed the audio setting page not always updating correctly
  • Many minor UI tweaks: made “move notes” menus more convenient so that closer clips are shown first, fixed tooltips in the chord tool, fixed updating with the editable scope in velocity map, fixed the pen tool behavior on mobile platforms

Version 3.5

  • Disabled all network-related features on mobile platforms
  • Added two UI flags for better control over mouse wheel behavior, notably for using mouse wheel for panning instead of zooming by default
  • Added UI option to disable most of the editor animations
  • Added UI flag to change the bottom mini-map appearance (toggled by B hotkey)
  • Added tooltips to sidebar buttons
  • UI improvements: fixed the pattern roll not updating with time signature changes, prettied up the cut point marks for the knife tool and note resizers on mobile platforms
  • Implemented duplicating automation tracks in the pattern roll
  • Fixed the project length being calculated incorrectly for rendering
  • Fixed font scanning so the app shouldn’t freeze on the very first run

Version 3.4

  • Added horizontal scrolling using shift + mouse wheel
  • When exporting MIDI, the track segments are grouped in the same way as you see them grouped in the pattern roll
  • All instances of selected clips in the pattern roll are now highlighted with the dashed header
  • Added ‘+’ button on the tools sidebar, which shows the new track dialog, or the menu to choose the instrument first; using the quill tool on any empty row will invoke the same menu or dialog
  • Fixed minor UI glitches on MIDI import and checkout, fixed the track range indicator not always updated properly, tweaked hotkeys a bit
  • Added a menu to move selected notes to another track, also available in the command palette with ‘:’ shortcut
  • Better support for file choosers on mobile platforms to allow exporting MIDI file to a custom location, e.g. iCloud container

Version 3.3

  • Added initial support for custom temperaments, the default list includes 22-EDO and 31-EDO; added commands to switch temperament or convert a piece into any other temperament
  • Added keyboard mapping page for instruments, allowing to overcome the limits of MIDI 1.0 for microtonal music, or just to re-map any key for whatever purposes
  • Forgive me father, for I have synthed: removed the built-in piano samples to reduce binary size (my OCD appreciates this immensely), and added a simple sine-like synth which works in any n-tone equal temperament out of the box; it sucks, but hopefully it will be improved in future
  • Added a command to switch to the most visible track/clip in the viewport, hotkey F3
  • Fixed note previewing for some instruments: now it sends note-off events after a delay
  • Minor UI tweaks: made animations a bit shorter and sharper, fixed several focus issues when deleting tracks, the resizable edge in note components now depends on the note width

Version 3.2

  • Added tempo dialog with “tap tempo” control, invoked either by clicking at tempo track nodes, or by hitting “Set one tempo” menu item in project->refactor menu or tempo track context menu
  • Fixed the old and super annoying rows tiling bug in OpenGL mode
  • Context menus in the sequencer are now only available via long right-click: instant rclick menu often gets in the way when misclicking / trying to switch to another track
  • Playback: will compute states of all present CC automations at the playhead position and apply them when playback starts, which helps a lot if you use pedal tracks or similar automations
  • Orchestra pit: if some instrument hasn’t loaded properly (e.g. plugin file missing), then the last valid instrument settings will be preserved in hope that it can be loaded correctly in the next launches; invalid instruments are shown as greyed out in the orchestra pit page, they also can be deleted, or made valid by adding a plugin node
  • Key signature dialog: right-click on any key will play the key
  • Lots of UI updates: tidied up the project info page and the dashboard, updated the colours list and the breadcrumbs control

Version 3.1

  • Added right-click context menus in the sequencer, version control and orchestra pit pages: the menu content is always the same as in the breadcrumbs control tail menu
  • Added a command to bring up the current instrument’s window, hotkey F4
  • Fixed some more UI glitches - most notably, focusing the piano roll scope on a track
  • Minor bugfixes in MIDI recording

Version 3.0

  • Added initial support for MIDI recording, hotkey F12
  • Added initial support for looping the playback over the selected scope, hotkey F11
  • Added quantization commands
  • Made annotations lengths adjustable
  • Added timeout for scanning fonts on the first run to avoid the app hanging on some systems
  • Minor UI updates for a prettier look and less glitching; added the command palette button in the headline and the timeline repeat sign
  • More tech debt has been paid down, this part of the update will hopefully be invisible
  • Added some documentation

Version 2.5

  • This is mostly a bugfix release: addressed some UX inconveniences and fixed a stupid crash
  • Added hotkeys for tweaking lengths of selected notes; also adding a note with a modifier key inserts a new note in a dragging mode
  • Made all hotkey-based beat/length-shift actions depend on the current zoom level
  • Implemented duplicating tracks in an interactive manner
  • Made all dialogs draggable
  • Enabled hardened runtime for macOS builds

Version 2.4

  • Added the command palette aka goto anything, toggled by ~ hotkey: the default mode is used for quick access to commands for the current context, the ‘/’ mode is used for quick access to projects list, ‘@’ mode to go to any timeline event or focus on any clip, and ‘!’ mode to construct chords from the text description (still experimental)
  • Added an option to display note names for a visual cue, toggled by the default hotkey ‘g’ (for ‘guides’)
  • Added an option to disable scales highlighting, toggled by the default hotkey ‘h’ (for ‘highlighting’)
  • Removed some shame from my heart by refactoring ugly bits of serialization code, also removed the legacy serializer which definitely did not spark joy, thus dropped support for v1 file format
  • Made it possible to control volume ramping amount with mouse wheel in the velocity map
  • Fixed some issues with switching between system/custom title bar
  • Fine-tuned the performance and piano roll behaviour
  • Added notarization for macOS builds

Version 2.3

  • Added support for aug/dim chords descriptions
  • Allow switching between custom and native title bar on Windows and Linux
  • Also display breadcrumbs in the title bar if possible to save some screen space
  • Added retrograde and melodic inversion to selection refactoring menu
  • Added shift-drag-to-copy for all timeline events
  • Go to next/previous anchor now jumps over clips in pattern mode
  • Reworked midi import, should fix importing controller tracks, key/time signatures and track names
  • Made plugins search less likely to stuck and cancellable with a click or escape keypress

Version 2.2

  • Long-overdue implementation of inline velocity map/editor (toggled by V button)
  • Arpeggiators can use advanced options, like length multiplier, inversion, randomness level (shift/ctrl/atl + arp button)
  • Refactored instruments managements to fix rare crashes on the orchestra pit page
  • Fixed shift-drag-to-copy for notes, which was broken even before v2 release
  • Fixed automation curves interpolation
  • Some refactorings for lesser memory usage

Version 2.1

  • Clips now can be muted/soloed
  • Patterns can be grouped by name/colour/instrument
  • Notes can be split into triplets/quadruplets/quintuplets/etc
  • Binary size is much smaller and more optimized overall, due to unity build

Version 2.0

  • Spent entire 2018 paying off the tech debt of version 1 (or tech mortgage, if you will), which was pretty much of a POC
  • Changed bundle ids to more consistent ones
  • Rewritten the backend side API’s from scratch
  • LOTS of refactorings, performance/stability fixes, etc - hopefully all future updates will be just incremental improvements

Getting started

UI overview


This is how the sequencer page looks like in Helio, as of version 3. There are other pages besides this, but you’ll spend majority of your time in the sequencer.

The UI is divided into the following sections:

They will be described below, but, before you dive in,

A little backstory and a couple of silly excuses

This project arose from the need for an advanced MIDI editor, something like Sublime Text for music.

I was also sick and tired of visual overstimulation, which most music tools tend to have more and more (just google some pictures for “digital audio workstation”). One of my main goals was to create a tool that feels right: one with an uncluttered and non-distractive user interface.

So, in general, I try to avoid adding UI controls if there is a way to do without them. As it turned out, though, there are a couple of challenges with that approach (for which I don’t see simple solutions, UX design is hard):

  • one challenge is to keep the UI simple, even minimalistic, while also not being disorienting,
  • another challenge is to keep the UI look and behave consistently across all platforms, both desktop and mobile.

If something feels misleading to you, please report it to help identify the main friction points.

Workspace navigation

The breadcrumb control on the top is responsible for navigating the workspace.

The Studio root node contains links to all available pages and open projects:


Workspace structure

Breadcrumbs show the hierarchy of the current page you’re on.

Under the hood, all pages have a tree-like structure that looks like this:

  • Dashboard for the projects list, a fancy logo, and a couple of buttons
  • Settings for choosing a language, audio drivers, playing with UI flags, etc
  • Orchestra pit for managing plugins and instruments on the stage
    • Instrument 1 page for setting up audio/MIDI routing for all plugins in your instrument
    • Instrument 2 page and so on
  • Project 1 page for the basic project info: title, author, etc
  • Project 2 page

Context menus

Note that all items in the breadcrumb control have their own context menus:


Creating a Project

When you first launch Helio, you should see a simple example project open in the editor. Here are a few steps that can help you get started:

  • to rename the project, click Example Project in the breadcrumb control, and you’ll be taken to the project info page, where you can edit some details,
  • after renaming, return to the piano roll page by pressing Alt + Left Arrow or by pressing the back button on the top left.
  • note that you can only edit one track at a time: use right-click to switch to another track (or long tap on mobile),
  • to play with arrangement, switch to the pattern roll by pressing Tab or Page Down, or by clicking the uppermost button in the left sidebar,
  • double-click any clip to return to the piano roll with that clip in focus; at this point you should get an idea of how the sequencer layout works.

To start a new project from scratch, go to the dashboard by pressing the Home key, or clicking the Studio node in the breadcrumbs. There you’ll see a list of recent projects, and a couple of buttons:

  • create an empty project,
  • open an existing project (this also imports MIDI files).

Switching between projects

There are several ways:

  • use the / hotkey to display the projects list in the command palette,
  • or hover the Studio item in the breadcrumb control to display a menu with all open projects,
  • the back and forward buttons are also useful at times; the associated hotkeys are Alt + Cursor Left and Alt + Cursor Right.


Instruments management

The most notable difference between Helio’s instrument management and that of the majority of DAWs and sequencers is that Helio separates instruments from projects.

Each project only stores the instrument references, so the instrument settings are saved in the application workspace settings rather than the project files.

Instruments are created and set up in a separate page, called Orchestra Pit.

The reason for implementing it this way was that in my workflow, I tend to use the same instruments for all of my projects. The app was designed primarily as a sketching and prototyping tool, and I usually have lots of sketches, so all the operations involving switching between projects, opening and closing them, or checking out in the version control, were ought to be as fast as possible, and not eat up all the memory.

Helio is probably not the best choice if your setup requires you to always have different instruments or instrument settings for each project, or if you want the project file to contain the instrument details.

On the other hand, if you happen to have an instrument library you’re comfortable with (e.g. VSL or a selected soundfonts collection), and you want to set it up once and forget it, you’ll probably like this approach.

Orchestra pit page

The orchestra pit page has two sections:

  • all found plugins are displayed on the left side,
  • all instruments on stage, created from those plugins, are on the right.


First, you want to scan for available plugins, there are two options in the orchestra pit menu:

  • either pick a specific folder to scan (note that all subfolder will be scanned as well),
  • or perform a global plugins scan: it tries to guess the most possible locations, e.g. Steinberg folders in Program Files, and scans them and all their subfolders.

Once you have a list of plugins, create an instrument using the plugin menu, so that it appears on the stage and can be assigned to your tracks.

Instrument details and routing

Double-click on any of the instruments to get to the instrument details page.


Most of the actions here, including audio and MIDI routing, are available through the menus.

Interacting with nodes:

  • left-click on the node will create a plugin window, it it has one, or just select it, if it doesn’t,
  • right-click on the node will just select it,
  • use mouse drag to connect sockets representing audio and MIDI inputs and outputs.

While it is possible to set up a multi-plugin instrument with audio/MIDI routing in Helio, the convenience of the instrument page was not of a particular concern: the development is rather focused on the sequencer functionality. If you are running it under Linux, it might be a good idea to add Carla as an instrument, and use it to manage VST/whatever plugins and routing.

Editing and arranging


On the top of the editor canvas, there’s a timeline control. To interact with it:

  • left click at the timeline to position the playhead,
  • middle-click to start the playback from that position,
  • right click to invoke the timeline events menu:


Timeline events include annotations, key signatures and time signatures, and they don’t affect the playback of your piece in any way, they are rather meant to provide a visual cue.

Manipulating the timeline events:

  • click on any event to focus the playhead at its position,
  • once focused, click again to edit or delete the event (displays a dialog),
  • drag to move, or shift-drag to duplicate the event.


Annotations are just text markers with optionally adjustable length:


Right-click on the annotation selects all notes of the active track up to the next annotation.

Time signatures

Time signatures simply define the way the vertical grid lines are aligned in the roll:


Right-click on the time signature selects all notes of the active track up to the next time signature.

If you need to manage complex rhythms, see this page.

Key signatures

Key signatures affect the way the rows are highlighted in the piano roll, but this can be disabled.


Apart from that, arpeggiators and a couple of other tools rely on key signatures to figure out the current harmonic context.


If you have enabled the playback loop over the selected scope, timeline will display the repeat signs:


This sidebar is responsible for track navigation and UI control.

Most buttons on the sidebars have keyboard shortcuts, which makes them kinda redundant, but they are displayed anyway for the sake of having a consistent UI on mobiles or touch-screen laptops, where you don’t have hotkeys.

  • sidebar-left-1 — switch the editor view between the piano roll and the pattern roll (Tab),
  • sidebar-left-2 — zoom out (Shift + Z), zoom in (Z), and zoom selection (Control + Tab),
  • sidebar-left-3 — jump over the timeline events (, and .),
  • sidebar-left-4 — toggle the velocity map (V),
  • sidebar-left-5 — UI flags that toggle scales highlighting and the note guides (H and G),
  • sidebar-left-6 — a simple waveform or spectrogram view.

This sidebar is responsible for editing tools and playback control:

  • sidebar-right-1 — toggle the playback loop over the selection (F11),
  • sidebar-right-2 — edit modes (1, 2, 3, 4),
  • sidebar-right-3 — some other tools - the chord tool and arpeggiators, if available,
  • sidebar-right-4 — copy and paste, undo and redo,
  • sidebar-right-5 — playback (Space or Enter) and recording (F12) control.

Piano roll

The piano roll always limits the editable scope to a single track. You will see all other tracks in a semi-transparent ghost mode. Most common interactions with the piano roll canvas are:

  • right-click on the inactive note to focus the editor to another track,
  • right-drag the empty space to pan the canvas:


Interacting with piano roll also depends on the current edit mode:

Edit modes

  • normal mode to manage selection and edit notes,
  • pen mode to add and edit notes,
    • alternatively, use it to delete notes or clips with right mouse button,
  • knife mode: cuts notes in the piano roll, cuts tracks in the pattern roll,
    • alternatively, use it to merge tracks or notes with right mouse button,
  • drag-only mode: a kind of auxiliary mode, hold Space to toggle it temporarily,
  • selection mode is only displayed on mobile platforms.

All notes, when edited, are aligned to the grid. The grid resolution (the density of barlines) depends on the zoom level and supports up to 1/64 notes. Tip: holding Alt while editing notes disables snapping to the grid.

All edits are undoable, and there is no limit to the number of undo actions available until the app is restarted. Additionally, each project saves the last 16 undo actions (32 on mobile platforms), which remain undoable after restarting the app. This limit can be changed by editing the main configuration file.

All changes are saved automatically: on exit, and on a timeout after the last change.

The editor relies heavily on hotkeys; feel free to explore available actions by browsing breadcrumb control menus or command palette.

Adding new tracks

Add new tracks by duplicating the existing ones (F5), or via project menu, or by cutting tracks with the knife tool in the pattern roll.

Velocity map

The velocity levels editor (toggled by V hotkey) provides a way to visualize and draw gradual increase/decrease in note volume.

As well as the piano roll, the velocity map limits its editable scope to the active track. But in addition, if any notes are selected, the editable scope is limited to the selection, to make it easier to draw more complex ramps for different chunks of the track:


At the moment of writing, only linear ramps are implemented:


You can also change note velocities without this editor, just by middle-button dragging the note components on the roll.

MIDI recording

The record button (F12) will try to auto-detect the available and enabled MIDI input device, or provide a choice if there are more than one (the choice is “remembered” and can be changed later in the settings page):


If the recording mode is on, but the playback has not started yet, it will wait until it receives the first MIDI event and start recording & playback.

In the piano roll mode, it always records to the selected track/clip:


In the pattern roll, it either records to the selected track/clip, or, if no piano clip is selected, it adds one, once the actual recording starts.

Pattern roll

You don’t necessarily need that editor. Helio was designed to be a hybrid linear-based/pattern-based sequencer, so you could just stay in the piano roll mode and treat your project as one big canvas.

However, the pattern roll is helpful for rearranging experiments:


Pattern roll also allows you to tweak some track parameters, like key offset of velocity multiplier. In future, it may shift towards more parametric sequencer features.

See also: track grouping

Global tempo

Pattern roll is also the place to edit various MIDI controller automation tracks - most notable, the tempo track(s):


The tempo track, as any other automation track, interpolates the controller value between nodes, and those tiny points are displayed at the exact times each new MIDI event is sent.

To interact with it:

  • delete nodes with right click,
  • use the pen tool (hotkey 2) to add nodes,
  • use the cursor tool (hotkey 1) to drag nodes or to adjust the interpolation curve,
  • click on the node to invoke the tempo dialog to set the exact BPM value, or to set tempo by tapping:


Tip: use the mouse wheel to quickly ajdust the tempo in this dialog.

Often, you only need one tempo for the whole song - for that, pick “Set one tempo” menu item in the tempo track menu, or project refactoring menu.

Mute and solo

Individual clips can be muted via the M hotkey or the context menu in the pattern roll. Except for automation, all clips can be soloed (with the S hotkey or via the context menu) for the convenience of isolating chunks of notes without disabling the tempo/pedal/etc. automation at the same time.

All clips that are explicitly or implicitly muted (muted by others) are displayed as dimmed:


Version control

The concept of version control comes from the software development world. If you’re not familiar with it, you can think of it as of creating “save points” in your project, and tracking changes made since the last time you saved.

The point of having a version control is lowering the friction of committing changes: any changes can be reset if you don’t like them, any saved revision can be restored later. Helio was started as a prototyping tool, a playground for ideas, where you’d want to have several variations of your sketch — hence the idea of having a built-in version control.

Notable use cases are:

  • saving a project state at some point, and resetting to any earlier saved state,
  • resetting some of the recent changes (think of it as of another mechanism of undoing things),
  • hiding and restoring back the most recent changes to get the idea of what have been done since the last commit,
  • synchronizing projects across devices.

The UI of the versions page is split in two parts:


The left side lists all changes in the project, compared to the current revision. Items in the list can be checked and unchecked: both committing and resetting changes are applied selectively.

The right side shows the tree of all revisions that you have saved. Note a couple of icons under each revision: they indicate whether the revision is available locally, or remotely, or both.

Getting microtonal

Before you get started with microtonal music, you will need two things:

  • Find a plugin (VST/whatever), which supports microtonal temperaments: here’s a list with some examples.
  • Set up keyboard mapping for that instrument: this needs to be done both in the plugin’s settings and in the host (this app), to overcome the limits of MIDI 1.0. The piano roll works as a microtonal keyboard with a wide key range from 0 up to 2048, and it needs to map every key over 16 MIDI channels, of 128 keys each; then those MIDI messages are sent to the plugin, which needs to know how to interpret them, or how to map them back from multi-channel data.

Setting up instruments

You can skip the instrument setup steps, if you only want to get familiar with microtonal scales. The default instrument in Helio is silly, but it works out of the box with all temperaments with no setup required, and should give you some idea of how things work.

Otherwise, once you’ve added an instrument to the stage, just pick “Edit keyboard mapping” menu item. The “keyboard mapping” here means mapping MIDI events routed from the Midi In node to the plugin node(s).

Keyboard mapping page

Note: this describes the key mapping on the host side, but you’ll need to set it up on the plugin’s side as well. Unfortunately, can’t help you with that, as it depends on the plugin, but here’s an example.

The page allows you to adjust key mappings manually and preview the mapped keys by clicking on them. The upper limit is set to 2048 keys - this is the maximum number of keys that can fit into 16 MIDI channels. Which would be enough to handle temperaments of size up to 192-EDO:


Some additional actions are available via context menu:

  • reset to the default mapping (modulo based),
  • load custom channel mapping(s) in Scala .kbm format,
  • copy/paste the mapping into/from the system clipboard as a string in Helio’s own format,
  • select one of the presets or save yours.


While you can set up virtually any custom mapping by hand, there are a couple of (sometimes) more convenient ways, described below.

Scala keyboard mapping

Note: don’t confuse Scala keyboard mapping (.kbm files) with Scala tuning files. The latter are not of much use for the piano roll, since it doesn’t care about cents and ratios - those are only needed by instruments.

Helio can load Scala keyboard mapping(s), including multichannel mappings which consist of a set of single mapping files with the same name followed by an underscore and a channel number. When you pick a .kbm file, Helio will search for “same_name_*.kbm” files to try to determine whether or not there are multiple channels’ mappings, and try to load them all.

Keep in mind that, on the sequencer side, the mapping will be reversed compared to the same mapping on the instrument side. The piano roll acts like a microtonal keyboard, which needs to overcome the limits of MIDI channels, and thus is mapping all the keys, which are above 127, across multiple channels.

// TODO examples

Helio keyboard mapping format

I think that Scala kbm format is obscure and unintuitive, so let me reinvent the wheel one more time and introduce another keyboard mapping format, supposed to be shorter, cleaner and kind of human-readable. You can use it on the keyboard mapping page by simply copying and pasting the mapping as a string.

Let’s start with an example. The entire multi-channel mapping for Pianoteq 31-EDO could be written like this:

0:0/14,31+ 31:0/15,31+ 62:0/16,31+ 93:0/1,31+ 124:0/2,31+ 155:0/3,31+ 186:0/4,31+ 217:0/5,31+ 248:0/6,31+ 279:0/7,31+ 310:0/8,31+

Which reads:

  • starting from key 0 of the piano roll, map it to the key 0 of channel 14, then map the next 31 keys in a sequential manner: for example, key 1 maps to 1/14, key 2 maps to 2/14, and so on,
  • starting from key 31, map it to the key 0 of channel 15, and, again, map the next 31 keys sequentially,
  • and so on.

Similarly, the 22-EDO Pianoteq mapping would look like this:

0:0/14,22+ 22:0/15,22+ 44:0/16,22+ 66:0/1,22+ 88:0/2,22+ 110:0/3,22+ 132:0/4,22+ 154:0/5,22+ 176:0/6,22+ 198:0/7,22+ 220:0/8,22+

For 34-EDO mapping you might want to start one octave lower since the key range is wider:

0:0/13,34+ 34:0/14,34+ 68:0/15,34+ 102:0/16,34+ 136:0/1,34+ 170:0/2,34+ 204:0/3,34+ 238:0/4,34+ 272:0/5,34+ 306:0/6,34+ 340:0/7,34+

Format description

First, the format assumes the default modulo-based mapping:

  • keys 0..127 are mapped as they are to channel 1,
  • keys 128..255 are mapped as 0..127 in channel 2, and so on.

Everything that differs from the default values is serialized. The serialized mapping is just a string divided by whitespaces into chunks.

Chunks follow this pattern: base:key/channel,key2/channel2,key3/channel3. Which means:

  • for the base key in the sequencer, the specified key/channel will be sent to the instrument,
  • then, for the base + 1 key in the sequencer, the next key and channel will be sent, and so on.

If each next key just incrementally moves by 1, the chunk could be shortened like this: base:key/channel,count+.

// TODO more examples (if you have set up keyboard mappings, which work well for some of your instruments, feel free to share them to improve these docs)

Switching temperaments

The most straightforward way to start playing around with microtonal scales is to convert any of your twelve-tone pieces (or a new project) into other temperament.


The project refactoring menus provides two choices:

  • the "Change temperament" command will simply switch the piano roll highlighting and update key signatures,
  • the "Convert to temperament" command will, in addition, update notes: the conversion is made using chromatic scale approximations - see the temperament model description - Helio will use these chromatic maps as the “least common denominators” among temperaments to convert from one to another.

All scale-related tools will only show those scales with octave size matched with current temperament (the piano roll doesn’t distinguish EDO’s from non-EDO’s, all that matters is the number of keys in octave, highlighting, key names, etc).


The default built-in temperaments list includes 12-edo, 19-edo, 22-edo and 31-edo.

And the built-in scales list only includes 7-tone scales for each of those temperaments, because there are several pieces of the app which still assume working with diatonic scales, e.g. the chord tool or the arpeggiator tool, - so given that limitation, using these tools with any built-in temperament or scale would make at least some kind of sense.

Adding a custom temperament

To add custom temperaments and their scales, follow the guide in the сonfigs page. Use the built-in temperaments and scales configuration files as a reference.

Recording MIDI from 12-tone keyboard

The app makes it possible to play and improvise on a standard 12-tone physical keyboard and record MIDI regardless of what temperament is used. For that, it uses the ‘chromatic mapping’ scale of the current temperament to readjust the incoming MIDI data so that all notes sound like their closest 12-tone equivalents.

Here’s an example of every key of chromatic scale played on a 12-tone MIDI keyboard and recorded in a 19-edo project:


This feature is on by default, but it can be turned off in the audio settings section just below the MIDI device box:


If you’re using a microtonal physical keyboard, make sure to uncheck this box so that the app doesn’t mess up MIDI input.


This section will describe setting up various microtonal plugins in Helio. For now, it’s just the Pianoteq example, if you managed to make any other plugin work, please share your findings.


Steps to set up a custom equal temperament:

  • In Pianoteq UI, navigate to the advanced tuning page:
    • there, create a custom microtonal temperament via the "Temperament" -> "Make equal temperament..." dropdown menu,
    • make sure to choose the "Full rebuild" option nearby instead of the "String tension" option,
    • in the "Keyboard mapping" -> "Extended layout for up to 16\*128 notes" dropdown menu, check "Multi-channel MIDI layout",
    • the "Main MIDI Channel" option in the same menu should be set to the default "MIDI channel 1".
  • In Helio UI, navigate to your instrument’s keyboard mapping page:
    • there, either select a keyboard mapping preset for your temperament from the menu, if it’s available: for now there are presets for 19-edo, 22-edo, 26-edo and 31-edo,
    • or, set up your own multi-channel mapping (see examples above on this page).

For more details on all Pianoteq’s tuning parameters refer to the manual.

Getting polymetric

Sometimes you might want to have several voices playing in different meters simultaneously. For example, a simple trick to make a piece more entertaining would be to write the drums part in 5/4, and all other voices in 4/4.

However, editing and rearranging that kind of rhythms on a standard 4/4 grid can quickly become a mess.

This page describes how to set up time signatures to avoid getting lost in bars and make piano/pattern roll grids more manageable, even for complex polymeters.

How time signatures work

Time signatures affect how the vertical grid lines are arranged across the canvas, which is to make aligning notes/clips more convenient and provide some visual cue.

Each time signature also defines how the metronome/click track will sound in the time signature’s scope.

There are two kinds of time signatures:

  • “Global” time signatures, which can be added to the timeline:


  • “Per-track” time signatures, which can be assigned to any track via menu or Alt + F2 hotkey:


Global time signatures can be dragged all over the timeline, and you can add as many of them as you want (e.g. shift-drag to copy them).

Per-track time signatures are anchored to their track’s position (although they can be dragged within the track’s range, which may be useful, if the track starts off-beat), and you can have exactly one per track.

You might want to use either of two kinds, or both, depending on your setup:

  • For simpler pieces, or, if you’re not using the pattern roll at all, you might only need global, timeline-based time signatures, often a single one.
  • If using the pattern roll and have lots of clips, try assigning time signatures to some parts of your piece in addition to global time signature(s) for more flexibility - see below the examples of how the timeline switches between them.
  • Finally, if you’re making complex rhythms, you might want to use per-track time signatures only. Even if you’re not making polymeters, time signatures attached to tracks make it easier to rearrange the piece and experiment.

Timeline behavior

Timeline will display global time signatures by default, and override them with time signatures of selected track(s), when possible.

In the pattern roll, it will try to aggregate time signatures for the entire row, assuming that one row is one “voice” (see also track grouping):


In the piano roll, timeline will simply switch to time signature(s) of the edited track, if any:



Note that making polytempo is not currently possible: the beat length is the same for all tracks. Time signatures make different bar sizes (and different snaps arrangements within a bar), but the global tempo track(s) affect the project as a whole.

Polyrhythm support is also poor; although you can think of polyrhythms as of polymeters on a smaller scale, that’s not very practical. There is basic support for tuplets (hotkeys Alt + 1 to Alt + 9):


But you can’t edit tuplet parts individually at the moment, which makes them only useful for drums, probably. Hopefully this will be improved in future.


The built-in metronome is toggled by Control + M hotkey.

Each time signature has its own metronome scheme: basically a short sequence of different click sounds, which defines how metronome accents are aligned within one bar:


Note that different time signatures with same meter can still have different metronome schemes.

The internal metronome instrument comes with 4 click sounds representing different click accents. You can customize them and pick your own samples in the instrument’s UI:

  • either select “Show UI” from the metronome instrument’s menu on the Orchestra Pit page,
  • or click on the metronome icon in the time signature dialog (a shortcut to the above).

See also: the default meters config

Tips and tricks

This page lists features, hacks and nuances, which might be handy, or non-obvious, or both.

Piano roll


While playback, Helio may sometimes draw red or yellow vertical warning lines:


These are the clipping and over-saturation warning markers:

  • red lines indicate problematic regions with clipping sound,

  • yellow warning lines will appear in the areas where the perceived loudness (a.k.a. the root mean square loudness) is way lower than the peak loudness, which is considered harmful unhealthy: in my setup it typically means that I have some redundant duplicate notes at the same place.

Spacebar panning

One quick way to switch between the current editing mode and the canvas panning mode is holding the Space key:


Dragging with the right mouse button does a similar thing, but it will also switch to another track, if clicked on any semi-transparent note.

Time measure tool

Hold the Space key, then click-and-drag over the timeline to measure time between two points at the timeline:


Sound probe tool

Finally, holding Space and clicking at the timeline is something I call “sound probe”, which is supposed to give an idea of what notes are playing at the given point:


Range selection

Click-and-drag at the timeline while holding any modifier key (Control/Alt/Shift) to select all notes or clips in some time range:


Velocity map fine-tuning

It’s possible to use the mouse wheel when dragging the velocity ramping tool to control how it blends with the original notes’ velocities. The main use case for that is fine-tuning the dynamics:


Resizing a group

Resize a group of notes proportionally by holding Shift:



Hold Shift to drag-and-copy notes in the piano roll, clips in the pattern roll, key/time signatures and annotations at the timeline:


Pen tool

Also hold Shift or any modifier key to change the behavior of the pen tool when adding notes. By default, the newly added note is edited in the transpose-and-resize mode. Alternatively, it’s the drag mode, more familiar:


UI flags

A couple of display options are available to provide a visual cue. They are toggled either in the navigation panel, or via hotkeys (G and H by default).

The first one is for displaying the note name guides:


Another one highlights the in-scale keys of the key signatures that are added to the timeline. If you prefer C Major coloring in the piano roll, just turn it off:


More UI flags

The audio monitor view can be toggled between two modes on click or tap, switching between the simple spectrogram mode and the waveform mode:


The mini-map mode can be toggled with B hotkey, or by clicking at any area except the screen range rectangle.

When in compact mode, it is stretched to fit all project:


Tip: when in full mode, the mini-map allows to draw a region to zoom at:


Chord tool

By double-clicking on a row in the piano roll, you invoke the chord tool:


It picks the current key signature from the timeline to determine what scale and root key to use to generate chords. Hence the main limitation of this tool: it can only generate chords that are easy to define with in-scale keys.

It can be dragged around by the center node — kinda helpful if you clicked the wrong row or position.

Since it depends on the harmonic context, it will do nothing when placed on the out-of-scale note (the grey row). It might be a good idea to make sure the scales highlighting is enabled to avoid confusion.

See also: piano roll hotkeys, refactoring options

Pattern roll

Knife tool

In my workflow, I’m often adding new tracks with a knife tool: even though there’s a normal way to add an empty track via project menu, or duplicate a track, I often end up having added some sketches in different places of a single sequence, and then, after switching to the pattern mode I see that they represent different parts, and can be cut into different tracks:


Merging tracks

Knife tool has an alternative mode: use right-click-&-drag (or long-tap-&-drag on mobile platforms) to merge one clip with another:


Clips and track grouping

In the example above, two split tracks remain on the same row because the tracks are grouped by name, and the knife tool keeps the track name the same. Pattern roll can also group tracks by color, or by instrument, or by track id — yet grouping by name works better for me.

So, the segments on one row might be either different tracks, or they also might be several instances (or “clips”) of the same track. Instances always share the same notes, and have the same name and color, but they can be slightly modified: have different position, key shift or volume multiplier, which is mainly meant for prototyping:


Note that when you select an item in the pattern roll, all its instances are highlighted with a dashed header: this helps to tell where are the “instances”, and where are other tracks of the same name or color on the same row. A quick way to convert an instance to a unique track is F6 hotkey.

Track grouping also affects MIDI export: all segments on one row will be exported as one track in the resulting MIDI file.

See also: pattern roll hotkeys


This page describes several refactoring options, available via selection menu and hotkeys:


Transposition and inversion

Not listed in the menu, but also handy: Shift + Up and Shift + Down hotkeys transpose the selected notes one octave up or down.

Also, Alt + Shift + Up and Alt + Shift + Down are used for transposition by a “fifth” - simply put, a transposition by +7 or -7 semitones in the 12-tone temperament, or by the closest equivalent of a perfect fifth in other temperaments, e.g. +18/-18 for 31-edo, etc.

The latter is useful for introducing short-term chord modulations to a “neighboring key” (the key that moves one step either direction on the circle of fifths).

Note that the above hotkeys also work on the pattern roll selection: creating track “instances” and modulating them is one of the easiest way of prototyping the structure of the piece.

Chord inversion

Use Control + Up and Control + Down for chord inversion (don’t confuse it with melodic inversion).

Chord inversion treats selected notes as chord(s); the lowest note in each chord moves one octave up (or the highest note moves one octave down), all others stay in place.

In-scale transposition

Use Alt + Up and Alt + Down hotkeys to transpose the selected notes using in-scale keys only:


The notes which are out of scale will be aligned up or down to the nearest in-scale keys.

More generally, you can think of it as “transposition using highlighted rows only”. For example, when the scales highlighting flag is off, it can be useful in microtonal temperaments to transpose notes using only those keys which approximate the 12-tone scale.

Melodic inversion

Alt + I hotkey applies melodic inversion to selected notes. This contrapuntal derivation is better described on Wikipedia; in short, it “flips” the melodic line upside down.


Alt + R hotkey applies another contrapuntal derivation, retrograde or “walking backward”.

Retrograde inversion, which is “backwards and upside down”, can be done by simply applying both inversion and retrograde.

Tip: use retrograde hotkey to quickly swap two neighbor chords:


Or to swap two notes like this:


Retrograde hotkey also works in the pattern roll, re-ordering all selected clips backwards for each row:


Cleanup overlaps

Alt + O hotkey removes duplicate notes and corrects lengths in a way that notes do not overlap each other.

Staccato and legato

Alt + S and Alt + L hotkeys apply staccato and legato commands to the selection. Staccato simply shortens all selected notes (Alt + Shift + S makes them as short as possible). Legato connects selected notes together in a way that each note lasts until another note starts:


Move to track

Pretty self-explanatory shorthand; this function is also available in the command palette: press : and select another track to move the selected notes to. For convenience, the “closest” tracks will be listed first.


This re-aligns the selected notes into one of the parallel modes of the same tonic.

You can think of it as introducing the in-place modal interchange.

As well as the chord tool, re-scaling assumes that the harmonic context is specified correctly. In the example below, the first section is marked as D Dorian, and all the notes in that section are in the key. Any out-of-scale notes will be left in their places.

Note that this function doesn’t change the key signature. Consider using it for introducing brief or transitory variations to bring more harmonic color.

If you want to re-scale the entire section of your piece, use the next option:

Quick rescale tool

Once you right-click on any key signature at the timeline, you can choose another scale, into which all the tracks will be translated. This affects all notes of all tracks up to the next key signature (or the very end of the project), and updates the key signature, which may be useful for experiments.

This example shows rescaling, along with some undo/redo to see the difference:



Arpeggiators submenu is available in the notes selection menu. If you have created any arpeggiators, you will also find a button on the right sidebar to apply one of them to selection.

How arpeggiators work

The idea behind arpeggiators was to remember any custom sequence of notes in their in-scale keys, so that the sequence doesn’t depend on the scale anymore, and later apply that scale-agnostic sequence to some chords in whatever different harmonic context.

That said, creating and using arpeggiators is tied to harmonic context, meaning arpeggiators rely on valid key signatures at the timeline.

Creating an arpeggiator

  • First, make sure you have a key signature, then create any sequence in that key and scale;
  • Select that sequence and hit Shift + A hotkey (or select a submenu item) to create a named arpeggiator from it.
  • After that, in any other place, apply that arpeggiator to any other selection (presumably, to some chords).

Arpeggiators is one of the unfinished parts of this app: there’s still no convenient way to edit or delete an arpeggiator, other than manually editing your arpeggiators.json in the documents directory. Hopefully this will be improved in future; as a workaround for editing arpeggiators, I’m maintaining a separate project just for arpeggiator sequences.

Command palette

The command palette control is inspired by ‘Goto Anywhere’ in Sublime Text or ‘Locator’ in QT Creator, and is meant for quick access to the commands available for the current context, and things like projects and timeline events.

Toggled by ~ or Control + P hotkeys by default:


Besides just commands, it supports special modes, triggered by typing a certain symbol. This symbol also acts as a hotkey to show the command palette in that mode:

  • / is for the project list,
  • : is for moving selected notes into another track (target tracks are ordered “closest first”),
  • @ is for the timeline events list + tracks list,
  • ! is for the chord compiler, which deserves a separate description:

Chord compiler

One of the modes of that command palette allows to generate chords based on the chord name decoding rules. This tool is not aware of any of the key signatures present at the timeline, all the chord’s notes are inferred from the given description.

Just hit ! and start typing a chord description, or pick some of the suggestions it provides:



Helio uses several configuration files, such as: scales, in-scale chords, temperaments, hotkeys, color schemes and translations.

For each of those configs, there can be up to three versions, which are loaded and merged in this order:

  • ones that a built-in into executable,
  • latest updates fetched from - they extend and override the built-in ones,
    • for example, translations, which is now the only resource updated in the runtime,
  • user’s configs - they extend and override the previous step.
    • for example, arpeggiators that you create in the app,
    • or any other configuration you might add and fill by hand.

Built-in configs


This config lists all chords displayed in the chord tool:

    A number of chords that are easy to define with in-scale keys.
    Sharp or flat near the number simply works as a halftone up/down.
  "chords": {
    "chord": [
      { "name": "3", "keys": "1 3 5" },
      { "name": "sus2", "keys": "1 2 5" },
      { "name": "sus4", "keys": "1 4 5" },
      //{ "name": "aug", "keys": "1 3 5#" },
      //{ "name": "dim", "keys": "1 3 5b" },
      { "name": "6", "keys": "1 3 5 6" },
      { "name": "7", "keys": "1 3 5 7" },
      { "name": "7 sus2", "keys": "1 2 5 7" },
      { "name": "7 sus4", "keys": "1 4 5 7" },
      { "name": "9", "keys": "1 3 5 7 9" },
      { "name": "add9", "keys": "1 3 5 9" },
      { "name": "add9 sus4", "keys": "1 4 5 9" },
      { "name": "add11", "keys": "1 3 5 11" }


This file lists all available temperaments, to which you can switch your project:

  "temperaments": {
    "temperament": [
        "id": "12edo",
        "name": "12 equal temperament",
        "period": "C C# D D# E F F# G G# A A# B",
        "highlighting": "2 2 1 2 2 2 1",
        "chromaticMap": "1 1 1 1 1 1 1 1 1 1 1 1"
        "id": "19edo",
        "name": "19 equal temperament",
        "period": "C C# Cx D D# Eb E E# F F# Fx G G# Ab A A# Bb B B#",
        "highlighting": "2 1 2 1 2 2 1 2 1 2 2 1",
        "chromaticMap": "2 1 2 1 2 2 1 2 1 2 2 1"
        "id": "22edo",
        "name": "22 equal temperament",
        "period": "C ^C vC# C# D Eb ^Eb vE E F Gb ^Gb vG G Ab ^Ab vA A Bb ^Bb vB B",
        "highlighting": "3 1 3 1 3 1 1 3 1 3 1 1",
        "chromaticMap": "3 1 3 1 3 1 1 3 1 3 1 1"
        "id": "26edo",
        "name": "26 equal temperament",
        "period": "D D# Ebb Eb E E# Fb F F# Fx Gb G G# Gx Ab A A# Bbb Bb B B# Cb C C# Cx Db",
        "highlighting": "2 2 3 1 3 2 2 2 2 3 2 2",
        "chromaticMap": "2 2 3 1 3 2 2 2 2 3 2 2"
        "id": "31edo",
        "name": "31 equal temperament",
        "period": "C Dbb C# Db C## D Ebb D# Eb D## E Fb E# F Gbb F# Gb F## G Abb G# Ab G## A Bbb A# Bb A## B Cb B#",
        "highlighting": "2 3 3 2 3 2 3 2 3 3 2 3",
        "chromaticMap": "2 3 3 2 3 2 3 2 3 3 2 3"

Temperaments define how highlighting works in the piano roll, including octave size and key names, and which scales are available to choose from. Temperament description also provides a chromatic approximation, which is used as the “least common denominator” to be able to convert a piece from one temperament to another.


Scales listed here are available to choose from in the key signature dialog, and in the rescale tool. Scales with octave size mismatching the current temperament’s octave size are ignored.

  "scales": {
    "scale": [

      // 12 edo scales; source: "The Scale Omnibus"
      { "period": 12, "name": "Ionian", "intervals": "2 2 1 2 2 2 1" },
      { "period": 12, "name": "Aeolian", "intervals": "2 1 2 2 1 2 2" },
      { "period": 12, "name": "Lydian", "intervals": "2 2 2 1 2 2 1" },
      { "period": 12, "name": "Mixolydian", "intervals": "2 2 1 2 2 1 2" },
      { "period": 12, "name": "Dorian", "intervals": "2 1 2 2 2 1 2" },
      { "period": 12, "name": "Phrygian", "intervals": "1 2 2 2 1 2 2" },
      { "period": 12, "name": "Locrian", "intervals": "1 2 2 1 2 2 2" },
      { "period": 12, "name": "Melodic Major", "intervals": "2 2 1 2 1 2 2" },
      { "period": 12, "name": "Melodic Minor", "intervals": "2 1 2 2 2 2 1" },
      { "period": 12, "name": "Harmonic Major", "intervals": "2 2 1 2 1 3 1" },
      { "period": 12, "name": "Harmonic Minor", "intervals": "2 1 2 2 1 3 1" },
      { "period": 12, "name": "Hungarian Major", "intervals": "3 1 2 1 2 1 2" },
      { "period": 12, "name": "Hungarian Minor", "intervals": "2 1 1 3 1 3 1" },
      { "period": 12, "name": "Neapolitan Major", "intervals": "1 2 2 2 2 2 1" },
      { "period": 12, "name": "Neapolitan Minor", "intervals": "1 2 2 2 1 3 1" },
      { "period": 12, "name": "Romanian Major", "intervals": "1 3 2 1 2 1 2" },
      { "period": 12, "name": "Romanian Minor", "intervals": "2 1 3 1 2 1 2" },
      { "period": 12, "name": "Enigmatic", "intervals": "1 3 2 2 2 1 1" },
      { "period": 12, "name": "Enigmatic Minor", "intervals": "1 2 3 2 2 1 1" },
      { "period": 12, "name": "Ionian Augmented", "intervals": "2 2 1 3 1 2 1" },
      { "period": 12, "name": "Lydian Augmented", "intervals": "2 2 2 2 1 2 1" },
      { "period": 12, "name": "Lydian Diminished", "intervals": "2 1 3 1 2 2 1" },
      { "period": 12, "name": "Lydian Dominant", "intervals": "2 2 2 1 2 1 2" },
      { "period": 12, "name": "Mixolydian Augmented", "intervals": "2 2 1 3 1 1 2" },
      { "period": 12, "name": "Phrygian Dominant", "intervals": "1 3 1 2 1 2 2" },
      { "period": 12, "name": "Ultraphrygian", "intervals": "1 2 1 3 1 1 3" },
      { "period": 12, "name": "Locrian Dominant", "intervals": "1 3 1 1 2 2 2" },
      { "period": 12, "name": "Superlocrian", "intervals": "1 1 2 2 2 2 2" },
      { "period": 12, "name": "Ultralocrian", "intervals": "1 2 1 2 2 1 3" },
      { "period": 12, "name": "Major Locrian", "intervals": "2 2 1 1 2 2 2" },
      { "period": 12, "name": "Leading Whole-Tone", "intervals": "2 2 2 2 2 1 1" },
      { "period": 12, "name": "Double Harmonic", "intervals": "1 3 1 2 1 3 1" },
      { "period": 12, "name": "Half Diminished", "intervals": "2 1 2 1 2 2 2" },
      { "period": 12, "name": "Altered Dominant", "intervals": "1 2 1 2 2 2 2" },
      { "period": 12, "name": "Blues Heptatonic", "intervals": "2 1 2 1 3 1 2" },
      { "period": 12, "name": "Blues Phrygian", "intervals": "1 2 2 1 1 3 2" },
      { "period": 12, "name": "Blues Modified", "intervals": "2 1 2 1 1 3 2" },
      { "period": 12, "name": "Blues Mixed", "intervals": "3 1 1 1 1 3 2" },
      { "period": 12, "name": "Blues Leading Tone", "intervals": "3 2 1 1 3 1 1" },
      { "period": 12, "name": "Rock'n'Roll", "intervals": "3 1 1 2 2 1 2" },

      // 19 edo scales; source:
      { "period": 19, "name": "Melodic Minor", "intervals": "2 3 2 3 3 3 3" },
      { "period": 19, "name": "Harmonic Minor", "intervals": "2 3 2 3 3 2 4" },
      { "period": 19, "name": "Harmonic Major", "intervals": "2 3 2 4 2 3 3" },
      { "period": 19, "name": "Deutone", "intervals": "1 3 3 3 3 3 3" },
      { "period": 19, "name": "Meantone", "intervals": "2 3 3 2 3 3 3" },
      { "period": 19, "name": "Ionian", "intervals": "3 3 2 3 3 3 2" },
      { "period": 19, "name": "Aeolian", "intervals": "3 2 3 3 2 3 3" },
      { "period": 19, "name": "Dorian", "intervals": "3 2 3 3 3 2 3" },
      { "period": 19, "name": "Lydian", "intervals": "3 3 3 2 3 3 2" },
      { "period": 19, "name": "Mixolydian", "intervals": "3 3 2 3 3 2 3" },
      { "period": 19, "name": "Locrian", "intervals": "2 3 3 2 3 3 3" },
      { "period": 19, "name": "Major Locrian", "intervals": "2 2 3 3 3 3 3" },
      { "period": 19, "name": "Phrygian", "intervals": "2 3 3 3 2 3 3 "},

      // 22 edo scales; source:
      { "period": 22, "name": "Harmonic Minor", "intervals": "4 2 3 4 2 5 2" },
      { "period": 22, "name": "Superpyth, diatonic", "intervals": "4 1 4 4 4 1 4" },
      { "period": 22, "name": "Just major", "intervals": "4 3 2 4 3 4 2" },
      { "period": 22, "name": "Natural minor", "intervals": "4 2 3 4 2 4 3" },
      { "period": 22, "name": "Tetrachordal major", "intervals": "4 3 2 4 4 3 2" },
      { "period": 22, "name": "Tetrachordal minor", "intervals": "4 2 3 4 2 3 4" },
      { "period": 22, "name": "Just harmonic minor", "intervals": "4 2 3 4 2 5 2" },
      { "period": 22, "name": "Just harmonic major", "intervals": "4 3 2 4 2 5 2" },
      { "period": 22, "name": "Just melodic minor", "intervals": "4 2 3 4 3 4 2" },
      { "period": 22, "name": "Superpyth harmonic minor", "intervals": "4 1 4 4 1 7 1" },
      { "period": 22, "name": "Superpyth harmonic major", "intervals": "4 4 1 4 1 7 1" },
      { "period": 22, "name": "Superpyth melodic minor", "intervals": "4 1 4 4 4 4 1" },
      { "period": 22, "name": "Superpyth double harmonic", "intervals": "1 7 1 4 1 7 1" },
      { "period": 22, "name": "Porcupine bright major", "intervals": "4 3 3 3 3 4 2" },
      { "period": 22, "name": "Porcupine bright minor", "intervals": "4 2 4 3 3 3 3" },
      { "period": 22, "name": "Porcupine dark minor", "intervals": "4 2 3 4 3 3 3" },

      // 26 edo scales; home-cooked approximations of 12-edo
      { "period": 26, "name": "Ionian", "intervals": "4 5 2 4 5 4 2" },
      { "period": 26, "name": "Aeolian", "intervals": "4 3 4 4 2 5 4" },
      { "period": 26, "name": "Lydian", "intervals": "4 5 4 2 5 4 2" },
      { "period": 26, "name": "Mixolydian", "intervals": "4 5 2 4 5 2 4" },
      { "period": 26, "name": "Dorian", "intervals": "4 3 4 4 5 2 4" },
      { "period": 26, "name": "Phrygian", "intervals": "2 5 4 4 2 5 4" },
      { "period": 26, "name": "Locrian", "intervals": "2 5 4 2 4 5 4" },
      { "period": 26, "name": "Melodic Major", "intervals": "4 5 2 4 2 5 4" },
      { "period": 26, "name": "Melodic Minor", "intervals": "4 3 4 4 5 4 2" },
      { "period": 26, "name": "Harmonic Major", "intervals": "4 5 2 4 2 7 2" },
      { "period": 26, "name": "Harmonic Minor", "intervals": "4 3 4 4 2 7 2" },
      { "period": 26, "name": "Neapolitan Major", "intervals": "2 5 4 4 5 4 2" },
      { "period": 26, "name": "Neapolitan Minor", "intervals": "2 5 4 4 2 7 2" },
      { "period": 26, "name": "Romanian Major", "intervals": "2 7 4 2 5 2 4" },
      { "period": 26, "name": "Romanian Minor", "intervals": "4 3 6 2 5 2 4" },

      // 31 edo scales; source:
      { "period": 31, "name": "Major", "intervals": "5 5 3 5 5 5 3" },
      { "period": 31, "name": "Natural Minor", "intervals": "5 3 5 5 3 5 5" },
      { "period": 31, "name": "Melodic Minor", "intervals": "5 3 5 5 5 5 3" },
      { "period": 31, "name": "Harmonic Major", "intervals": "5 5 3 5 3 7 3" },
      { "period": 31, "name": "Harmonic Minor", "intervals": "5 3 5 5 3 7 3" },
      { "period": 31, "name": "Major-Minor", "intervals": "5 5 3 5 3 5 5" },
      { "period": 31, "name": "Septimal Natural Minor", "intervals": "5 2 6 5 2 5 6" },
      { "period": 31, "name": "Neutral Diatonic Mixolydian", "intervals": "4 4 5 4 4 5 5" },
      { "period": 31, "name": "Neutral Diatonic Lydian", "intervals": "4 5 4 4 5 5 4" },
      { "period": 31, "name": "Neutral Diatonic Phrygian", "intervals": "5 4 4 5 5 4 4" },
      { "period": 31, "name": "Neutral Diatonic Dorian", "intervals": "4 4 5 5 4 4 5" },
      { "period": 31, "name": "Neutral Diatonic Hypolydian", "intervals": "4 5 5 4 4 5 4" },
      { "period": 31, "name": "Neutral Diatonic Hypophrygian", "intervals": "5 5 4 4 5 4 4" },
      { "period": 31, "name": "Neutral Diatonic Hypodorian", "intervals": "5 4 4 5 4 4 5" },
      { "period": 31, "name": "Hemiolic Chromatic Mixolydian", "intervals": "2 2 9 2 2 9 5" },
      { "period": 31, "name": "Hemiolic Chromatic Lydian", "intervals": "2 9 2 2 9 5 2" },
      { "period": 31, "name": "Hemiolic Chromatic Phrygian", "intervals": "9 2 2 9 5 2 2" },
      { "period": 31, "name": "Hemiolic Chromatic Dorian", "intervals": "2 2 9 5 2 2 9" },  
      { "period": 31, "name": "Hemiolic Chromatic Hypolydian", "intervals": "2 9 5 2 2 9 2" },
      { "period": 31, "name": "Hemiolic Chromatic Hypophrygian", "intervals": "9 5 2 2 9 2 2" },
      { "period": 31, "name": "Hemiolic Chromatic Hypodorian", "intervals": "5 2 2 9 2 2 9" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Mixolydian", "intervals": "2 3 8 2 3 8 5" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Lydian", "intervals": "3 8 2 3 8 5 2" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Phrygian", "intervals": "8 2 3 8 5 2 3" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Dorian", "intervals": "2 3 8 5 2 3 8" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Hypolydian", "intervals": "3 8 5 2 3 8 2" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Hypophrygian", "intervals": "8 5 2 3 8 2 3" },
      { "period": 31, "name": "Ratio 2:3 Chromatic Hypodorian", "intervals": "5 2 3 8 2 3 8" },
      { "period": 31, "name": "Intense Diatonic Mixolydian", "intervals": "3 5 5 3 5 5 5" },
      { "period": 31, "name": "Intense Diatonic Phrygian", "intervals": "5 3 5 5 5 3 5" },
      { "period": 31, "name": "Intense Diatonic Dorian", "intervals": "3 5 5 5 3 5 5" },
      { "period": 31, "name": "Intense Diatonic Hypolydian", "intervals": "5 5 5 3 5 5 3" },
      { "period": 31, "name": "Intense Diatonic Hypophrygian", "intervals": "5 5 3 5 5 3 5" },
      { "period": 31, "name": "Soft Diatonic Mixolydian", "intervals": "2 5 6 2 5 6 5" },
      { "period": 31, "name": "Soft Diatonic Lydian", "intervals": "5 6 2 5 6 5 2" },
      { "period": 31, "name": "Soft Diatonic Phrygian", "intervals": "6 2 5 6 5 2 5" },
      { "period": 31, "name": "Soft Diatonic Dorian", "intervals": "2 5 6 5 2 5 6" },
      { "period": 31, "name": "Soft Diatonic Hypolydian", "intervals": "5 6 5 2 5 6 2" },
      { "period": 31, "name": "Soft Diatonic Hypophrygian", "intervals": "6 5 2 5 6 2 5" },
      { "period": 31, "name": "Soft Diatonic Hypodorian", "intervals": "5 2 5 6 2 5 6" }


Meters listed here are available to choose from in the time signature dialog.

Each meter comes with a metronome, which is described using “Oona Pana” scheme, suggested by Rods Bobavich - a simplified, but handy way to describe musical rhythms, which is also easy to read and edit manually.

Metronome schemes listed here are just the default ones, and they can be edited for each time signature separately in the time signature dialog.

  "meters": {
    "meter": [
        "name": "Common time",
        "time": "4/4",
        "metronome": "oona pana"
        "name": "Alla breve",
        "time": "2/4",
        "metronome": "oona"
        "name": "Waltz time",
        "time": "3/4",
        "metronome": "oonapa"
        "time": "5/4",
        "metronome": "oonapa pana"
        "time": "6/4",
        "metronome": "oonapa panapa"
        "time": "7/8",
        "metronome": "oonapa pana papa"
        "time": "9/8",
        "metronome": "oonapa panapa panapa"
        "time": "10/8",
        "metronome": "oona panapa pana panapa"
        "time": "11/8",
        "metronome": "oona papa oona pana panapa"
        "time": "13/8",
        "metronome": "oonapa panapa panapa pana papa"


See the hotkeys page.


The translations file is too big to be included here; if you want to help proofread and improve the translation for your native language, please follow this link.

The translations are updated in the runtime, if there are any changes: the latest translations are saved in the translations.helio file in the app’s config directory.

User configs

To override or extend the built-in data, you can create a file with one of these names in your documents directory:

  • chords.json
  • scales.json
  • meters.json
  • temperaments.json
  • etc.

Custom scales

Let’s say, you want to add a scale - here’s the example content for scales.json:

  "scales": {
    "scale": [
      { "period": 12, "name": "Oriental", "intervals": "1 3 1 1 3 1 2" }

What it means:

  • "period": 12 - this scale will be available only in twelve-tone projects,
  • "name": "Oriental" - scales are merged by name; if the built-in list contained a scale with such name, it would be replaced,
  • "intervals": "1 3 1 1 3 1 2" - this one is a heptatonic scale, i.e. it contains 7 intervals.

Custom temperaments

Or, if you want to add a temperament, create temperaments.json; for example, let’s add 24-EDO:

  "temperaments": {
    "temperament": [
        "id": "24edo",
        "name": "24 equal temperament",
        "period": "C ^C C# vD D ^D Eb vE E ^E F ^F F# vG G ^G Ab vA A ^A Bb vB B ^B",
		"periodRange": 2.0,
        "highlighting": "3 4 3 4 3 4 3",
        "chromaticMap": "2 2 2 2 2 2 2 2 2 2 2 2"

What it means:

  • id - if the built-in list contained a temperament with such id, it would be replaced,
  • name - this is displayed in the menus,
  • period - key names separated by whitespace; the number of keys defines the octave size,
  • periodRange - the pitch range that makes up a period, defaults 2.0 representing one octave; for nonoctave tunings use 3.0 for the duodecime used in the Bohlen-Pierce tuning or 1.5 for the pure fifth, used in the Carlos Alpha, Beta and Gamma tunings; for backward compatibility, if this parameter isn’t given, Helio assumes one octave; this parameter only affects the built-in instrument at the moment,
  • highlighting - the default highlighting scheme in the piano roll, i.e. which rows are highlighted as “white keys” by default,
  • chromaticMap - this is used to convert temperaments; here, since 24-EDO just divides the 12-tone semitone in two, the chromatic map just jumps over quarter-tones. …

You might want to add some scales for it, for example:

  "scales": {
    "scale": [
      // append this list to your scales:
      { "period": 24, "name": "Maqam Nahfat", "intervals": "3 3 4 4 4 2 4" },
      { "period": 24, "name": "Maqam Saba", "intervals": "3 3 2 6 2 4 4" },
      { "period": 24, "name": "Maqam Sabr Jadid", "intervals": "3 3 2 6 2 6 2" }
      // etc, etc.
      // (source:

Custom arpeggiators

Arpeggiators are created in the app, you will find them saved in arpeggiators.json. You can edit this file by hand, but you probably won’t need to.


This page simply lists sections of the default hotkeys configuration file. Hopefully the command names are descriptive enough.

If you don’t see any hotkeys here, you’re reading the markdown source of this page, please visit

Hotkeys for all pages

    "receiver": "MainLayout",
    "keyPress": [

      // Command Palette aka Spotlight Search aka Goto Anything:
      { "command": "CommandPalette", "key": "`" },
      { "command": "CommandPalette", "key": "Control + P" },
      { "command": "CommandPalette", "key": "Command + P" },
      { "command": "CommandPalette", "key": "Control + G" },
      { "command": "CommandPalette", "key": "Command + G" },

      // Quick access to command palette modes - /, :, !, @
      { "command": "CommandPaletteWithMode", "key": "/" },
      { "command": "CommandPaletteWithMode", "key": "Shift + 1" },
      { "command": "CommandPaletteWithMode", "key": "Shift + 2" },
      { "command": "CommandPaletteWithMode", "key": "Shift + ;" },

      { "command": "ShowPreviousPage", "key": "Command + Cursor Left" },
      { "command": "ShowPreviousPage", "key": "Control + Cursor Left" },
      { "command": "ShowPreviousPage", "key": "Alt + Cursor Left" },
      { "command": "ShowNextPage", "key": "Command + Cursor Right" },
      { "command": "ShowNextPage", "key": "Control + Cursor Right" },
      { "command": "ShowNextPage", "key": "Alt + Cursor Right" },

      { "command": "SwitchToEditMode", "key": "Page Up" },
      { "command": "SwitchToArrangeMode", "key": "Page Down" },
      { "command": "SwitchToVersioningMode", "key": "Control + S" },
      { "command": "SwitchToVersioningMode", "key": "Command + S" },

Common hotkeys for editing and arranging

    "receiver": "SequencerLayout",
    "keyPress": [

      { "command": "SwitchBetweenRolls", "key": "Tab" },

      { "command": "ExportMidi", "key": "Control + E" },
      { "command": "ExportMidi", "key": "Command + E" },

      { "command": "RenderToWAV", "key": "Control + R" },
      { "command": "RenderToWAV", "key": "Command + R" },
      { "command": "RenderToFLAC", "key": "Control + Shift + R" },
      { "command": "RenderToFLAC", "key": "Command + Shift + R" }

Piano roll

    "receiver": "PianoRoll",
    "keyPress": [

      // Undo/redo:
      { "command": "Undo", "key": "Command + Z" },
      { "command": "Undo", "key": "Control + Z" },
      { "command": "Redo", "key": "Command + Shift + Z" },
      { "command": "Redo", "key": "Control + Shift + Z" },
      { "command": "Redo", "key": "Command + Y" },
      { "command": "Redo", "key": "Control + Y" },

      // Copy
      { "command": "CopyEvents", "key": "Command + C" },
      { "command": "CopyEvents", "key": "Control + C" },
      { "command": "CopyEvents", "key": "Command + Insert" },
      { "command": "CopyEvents", "key": "Control + Insert" },

      // Cut
      { "command": "CutEvents", "key": "Command + X" },
      { "command": "CutEvents", "key": "Control + X" },
      { "command": "CutEvents", "key": "Shift + Delete" },

      // Cut selection to the new track
      { "command": "NewTrackFromSelection", "key": "Control + Shift + X" },
      { "command": "NewTrackFromSelection", "key": "Command + Shift + X" },

      // Delete
      { "command": "DeleteEvents", "key": "X" },
      { "command": "DeleteEvents", "key": "Delete" },
      { "command": "DeleteEvents", "key": "Backspace" },

      // Paste
      { "command": "PasteEvents", "key": "Command + V" },
      { "command": "PasteEvents", "key": "Control + V" },
      { "command": "PasteEvents", "key": "Shift + Insert" },

      // Playback/record control
      { "command": "TransportStop", "key": "Stop" },
      { "command": "TransportStop", "key": "Escape" },
      { "command": "TransportPlaybackStart", "key": "Play" },
      { "command": "TransportPlaybackStart", "key": "Return" },
      { "command": "TransportRecordingAwait", "key": "F12" },
      { "command": "TransportRecordingAwait", "key": "Control + Return" },
      { "command": "TransportRecordingAwait", "key": "Command + Return" },
      { "command": "TransportRecordingStart", "key": "Shift + Return" },
      { "command": "ToggleLoopOverSelection", "key": "F11" },

      // Navigation
      { "command": "ZoomIn", "key": "Z" },
      { "command": "ZoomOut", "key": "Shift + Z" },
      { "command": "ZoomEntireClip", "key": "Alt + Z" },
      { "command": "ZoomEntireClip", "key": "Command + Tab" },
      { "command": "ZoomEntireClip", "key": "Control + Tab" },
      { "command": "TimelineJumpNext", "key": "." },
      { "command": "TimelineJumpPrevious", "key": "," },
      { "command": "TimelineJumpHome", "key": "Home" },
      { "command": "TimelineJumpEnd", "key": "End" },

      // Selection
      { "command": "SelectAllEvents", "key": "Command + A" },
      { "command": "SelectAllEvents", "key": "Control + A" },

      // Edit selection
      { "command": "ToggleMuteClips", "key": "M" },
      { "command": "ToggleSoloClips", "key": "S" },
      { "command": "RenameTrack", "key": "F2" },
      { "command": "SetTrackTimeSignature", "key": "Alt + F2" },
      { "command": "TempoUp1Bpm", "key": "Shift + +" },
      { "command": "TempoDown1Bpm", "key": "Shift + -" },
      { "command": "BeatShiftLeft", "key": "Cursor Left" },
      { "command": "BeatShiftRight", "key": "Cursor Right" },
      { "command": "LengthDecrease", "key": "Shift + Cursor Left" },
      { "command": "LengthIncrease", "key": "Shift + Cursor Right" },
      { "command": "TransposeUp", "key": "Cursor Up" },
      { "command": "TransposeDown", "key": "Cursor Down" },
      { "command": "TransposeScaleKeyUp", "key": "Alt + Cursor Up" },
      { "command": "TransposeScaleKeyDown", "key": "Alt + Cursor Down" },
      { "command": "TransposeOctaveUp", "key": "Shift + Cursor Up" },
      { "command": "TransposeOctaveDown", "key": "Shift + Cursor Down" },
      { "command": "TransposeFifthUp", "key": "Shift + Alt + Cursor Up" },
      { "command": "TransposeFifthDown", "key": "Shift + Alt + Cursor Down" },
      { "command": "MakeStaccato", "key": "Alt + S" },
      { "command": "MakeStaccatissimo", "key": "Shift + Alt + S" },
      { "command": "MakeLegato", "key": "Alt + L" },

      // Refactor selection
      { "command": "Retrograde", "key": "Alt + R" },
      { "command": "MelodicInversion", "key": "Alt + I" },
      { "command": "CleanupOverlaps", "key": "Alt + O" },
      { "command": "NotesVolumeUp", "key": "+" },
      { "command": "NotesVolumeDown", "key": "-" },
      { "command": "NotesVolumeRandom", "key": "Alt + +" },
      { "command": "NotesVolumeFadeOut", "key": "Alt + -" },
      { "command": "InvertChordUp", "key": "Control + Cursor Up" },
      { "command": "InvertChordUp", "key": "Command + Cursor Up" },
      { "command": "InvertChordDown", "key": "Control + Cursor Down" },
      { "command": "InvertChordDown", "key": "Command + Cursor Down" },

      // Multiplets
      { "command": "Tuplet1", "key": "Alt + 1" },
      { "command": "Tuplet2", "key": "Alt + 2" },
      { "command": "Tuplet3", "key": "Alt + 3" },
      { "command": "Tuplet4", "key": "Alt + 4" },
      { "command": "Tuplet5", "key": "Alt + 5" },
      { "command": "Tuplet6", "key": "Alt + 6" },
      { "command": "Tuplet7", "key": "Alt + 7" },
      { "command": "Tuplet8", "key": "Alt + 8" },
      { "command": "Tuplet9", "key": "Alt + 9" },

      // Quantization
      { "command": "QuantizeTo1_1", "key": "Control + 1" },
      { "command": "QuantizeTo1_2", "key": "Control + 2" },
      { "command": "QuantizeTo1_4", "key": "Control + 3" },
      { "command": "QuantizeTo1_8", "key": "Control + 4" },
      { "command": "QuantizeTo1_16", "key": "Control + 5" },
      { "command": "QuantizeTo1_32", "key": "Control + 6" },

      // Edit modes
      { "command": "EditModeDefault", "key": "1" },
      { "command": "EditModeDraw", "key": "2" },
      { "command": "EditModeKnife", "key": "3" },
      { "command": "EditModePan", "key": "4" },

      // Version control
      { "command": "VersionControlToggleQuickStash", "key": "Shift + Tab" },

      // Panels
      { "command": "ShowArpeggiatorsPanel", "key": "A" },
      { "command": "CreateArpeggiatorFromSelection", "key": "Shift + A" },
      { "command": "ShowRescalePanel", "key": "R" },
      { "command": "ShowScalePanel", "key": "S" },
      { "command": "ShowChordPanel", "key": "C" },

      // Other toggles
      { "command": "ToggleScalesHighlighting", "key": "H" },
      { "command": "ToggleNoteNameGuides", "key": "G" },
      { "command": "ToggleBottomMiniMap", "key": "B" },
      { "command": "ToggleVolumePanel", "key": "V" },
      { "command": "ToggleMetronome", "key": "Control + M" },
      { "command": "ToggleMetronome", "key": "Command + M" },

      // Various
      { "command": "DuplicateTrack", "key": "F5" },
      { "command": "SwitchToClipInViewport", "key": "F3" },
      { "command": "EditCurrentInstrument", "key": "F4" }
    "keyDown": [
      { "command": "StartDragViewport", "key": "Spacebar" }
    "keyUp": [
      { "command": "EndDragViewport", "key": "Spacebar" }

Pattern roll

    "receiver": "PatternRoll",
    "keyPress": [

      // Undo/redo
      { "command": "Undo", "key": "Command + Z" },
      { "command": "Undo", "key": "Control + Z" },
      { "command": "Redo", "key": "Command + Shift + Z" },
      { "command": "Redo", "key": "Control + Shift + Z" },
      { "command": "Redo", "key": "Command + Y" },
      { "command": "Redo", "key": "Control + Y" },

      // Delete clips
      { "command": "DeleteClips", "key": "X" },
      { "command": "DeleteClips", "key": "Delete" },
      { "command": "DeleteClips", "key": "Backspace" },

      // Playback control
      { "command": "TransportStop", "key": "Stop" },
      { "command": "TransportStop", "key": "Escape" },
      { "command": "TransportPlaybackStart", "key": "Play" },
      { "command": "TransportPlaybackStart", "key": "Return" },
      { "command": "TransportRecordingStart", "key": "Shift + Return" },
      { "command": "TransportRecordingAwait", "key": "Control + Return" },
      { "command": "TransportRecordingAwait", "key": "Command + Return" },
      { "command": "TransportRecordingAwait", "key": "F12" },
      { "command": "ToggleLoopOverSelection", "key": "F11" },

      // Navigation
      { "command": "ZoomIn", "key": "Z" },
      { "command": "ZoomOut", "key": "Shift + Z" },
      { "command": "ZoomEntireClip", "key": "Alt + Z" },
      { "command": "ZoomEntireClip", "key": "Command + Tab" },
      { "command": "ZoomEntireClip", "key": "Control + Tab" },
      { "command": "TimelineJumpNext", "key": "." },
      { "command": "TimelineJumpPrevious", "key": "," },
      { "command": "TimelineJumpHome", "key": "Home" },
      { "command": "TimelineJumpEnd", "key": "End" },

      // Selection
      { "command": "SelectAllClips", "key": "Command + A" },
      { "command": "SelectAllClips", "key": "Control + A" },

      // Quantization
      { "command": "QuantizeTo1_1", "key": "Control + 1" },
      { "command": "QuantizeTo1_2", "key": "Control + 2" },
      { "command": "QuantizeTo1_4", "key": "Control + 3" },
      { "command": "QuantizeTo1_8", "key": "Control + 4" },
      { "command": "QuantizeTo1_16", "key": "Control + 5" },
      { "command": "QuantizeTo1_32", "key": "Control + 6" },

      // Edit modes
      { "command": "EditModeDefault", "key": "1" },
      { "command": "EditModeDraw", "key": "2" },
      { "command": "EditModeKnife", "key": "3" },
      { "command": "EditModePan", "key": "4" },

      // Grouping
      { "command": "PatternsGroupByName", "key": "Q" },
      { "command": "PatternsGroupByColour", "key": "W" },
      { "command": "PatternsGroupByInstrument", "key": "E" },
      { "command": "PatternsGroupById", "key": "R" },

      // Version control
      { "command": "VersionControlToggleQuickStash", "key": "Shift + Tab" },

      // Edit selection
      { "command": "ToggleMuteClips", "key": "M" },
      { "command": "ToggleSoloClips", "key": "S" },
      { "command": "RenameTrack", "key": "F2" },
      { "command": "SetTrackTimeSignature", "key": "Alt + F2" },
      { "command": "TempoUp1Bpm", "key": "Shift + +" },
      { "command": "TempoDown1Bpm", "key": "Shift + -" },
      { "command": "ClipVolumeUp", "key": "+" },
      { "command": "ClipVolumeDown", "key": "-" },
      { "command": "ClipTransposeUp", "key": "Cursor Up" },
      { "command": "ClipTransposeDown", "key": "Cursor Down" },
      { "command": "ClipTransposeOctaveUp", "key": "Shift + Cursor Up" },
      { "command": "ClipTransposeOctaveDown", "key": "Shift + Cursor Down" },
      { "command": "ClipTransposeFifthUp", "key": "Shift + Alt + Cursor Up" },
      { "command": "ClipTransposeFifthDown", "key": "Shift + Alt + Cursor Down" },
      { "command": "BeatShiftLeft", "key": "Cursor Left" },
      { "command": "BeatShiftRight", "key": "Cursor Right" },
      { "command": "Retrograde", "key": "Alt + R" },

      // Various
      { "command": "ToggleBottomMiniMap", "key": "B" },
      { "command": "ToggleVolumePanel", "key": "V" },
      { "command": "ToggleMetronome", "key": "Control + M" },
      { "command": "ToggleMetronome", "key": "Command + M" },
      { "command": "DuplicateTrack", "key": "F5" },
      { "command": "InstanceToUniqueTrack", "key": "F6" },
      { "command": "EditCurrentInstrument", "key": "F4" }
    "keyDown": [
      { "command": "StartDragViewport", "key": "Spacebar" }
    "keyUp": [
      { "command": "EndDragViewport", "key": "Spacebar" }

Version control page

    "receiver": "VersionControlStage",
    "keyPress": [
      { "command": "VersionControlSelectAll", "key": "Control + A" },
      { "command": "VersionControlSelectNone", "key": "Escape" },
      { "command": "VersionControlCommitSelected", "key": "Return" },
      { "command": "VersionControlResetSelected", "key": "Backspace" },
      { "command": "VersionControlResetSelected", "key": "Delete" },
      { "command": "VersionControlCommitAll", "key": "Shift + Return" },
      { "command": "VersionControlCommitAll", "key": "Shift + Return" },
      { "command": "VersionControlResetAll", "key": "Shift + Backspace" },
      { "command": "VersionControlResetAll", "key": "Shift + Delete" },

      // Sync all revisions - only works when logged in
      { "command": "VersionControlSyncAll", "key": "F5" },

      // Stash all changes or apply stashed changes
      { "command": "VersionControlToggleQuickStash", "key": "Tab" }