UPDATE: the documentation is now located here, with much better formatting.
Acheron is an Electron-based recreation of Elysium, a probabilistic generative midi sequencer. (https://github.com/mmower/elysium)
Demo video by hellvalleyskytrees here: https://www.youtube.com/watch?v=BkXd8Xn45_k
Download the latest Acheron release here: https://github.com/SongSing/acheron/releases
the current version as of this writing is Acheron-1.1.1-win.zip
Extract the zip file and run Acheron.exe, then enable the built in tokens in the Manage Tokens window, as described below.
Please note that Acheron is a MIDI sequencer, and as such produces no sound on its own.
You'll need a Digital Audio Workstation and MIDI loopback driver, or a MIDI interface and a physical MIDI device.
Visit the GitHub page for more information, or to contribute: https://github.com/SongSing/acheron
The following is a list of terms used by Acheron and their definitions, including information on their properties when applicable:
Menu Bar:
At the top of the window. Contains the following items:
File:
Open Composition (Ctrl+O)
Save Composition as (Ctrl+S)
Close (Ctrl+W)
View:
Toggle Full Screen (F11)
Help:
Documentation
Links to this page
Troubleshooting
Links to the troubleshooting section of README.md on the Acheron GitHub.
Report a Bug
Links to the 'New Issue' page on the Acheron GitHub.
Credits
Links to the credits section of README.md on the Acheron GitHub.
Composition:
An Acheron document.
Options that apply to the whole composition (or all compositions) are located in the bar at the bottom center of the window.
These include:
Play/Pause (or press enter)
Settings, including:
Play notes on click
Wrap playheads
When wrap playheads is on, playheads that exit any side of the grid will apear on the opposite side.
Show confirmation prompts when removing things
MIDI outputs
Here you can select which output or outputs you want Acheron to send MIDI data to.
If you want to use Acheron with your DAW of choice rather than a hardware device, you'll need a midi loopback driver such as loopmidi:
https://www.tobias-erichsen.de/software/loopmidi.html
Manage Tokens
This is where you can add and enable/disable token types.
Tokens must be enabled here to add them to a composition:
The first time you run Acheron, click Manage Tokens, then enable all of the tokens.
IMPORTANT: If you don't see any tokens in the Manage Tokens window, please make sure the token search paths include /tokens/ in the root of the Acheron Folder.
Optionally you may choose a keyboard shortcut for each token type.
Show/Hide inspector
Toggles visibility of the righthand panel
Toggle MultiLayer Mode
Allows you to view all layers at once. Note that you can still add and remove tokens in this mode.
Report a Bug
Links to the 'New Issue' page on the Acheron GitHub.
Tick:
Time between beats, defined by the player or layer tempo.
Hex:
One of the 204 hexagonal cells in the grid at the center of the window, each corresponding to a musical note on the harmonic table:
https://en.wikipedia.org/wiki/Harmonic_table_note_layout
LFO:
Low frequency oscillator. Can be used to control most properties, by selecting 'lfo' in the control mode menu next to the propery name.
When a property's control mode is set to lfo, a button appears under the property, allowing you to edit the properties of the lfo. These include:
LFO Type
Can be set to Sin, Square, Random, Sequence, or Sawtooth
Minimum Value
Maximum Value
Period
The time it takes the lfo to complete a cycle.
Low Period (square only)
the time spent every cycle at the minimum value
High Period (square only)
the time spent every cycle at the maximum value
Properties:
Properties are located in the panels on the left and right sides of the window.
The lefthand panel contains global (player tab) and layer specific (layer tab) properties.
The righthand panel contains properties relating to individual tokens.
To change the control mode of a property, use the menu immediately to the right of the property name.
Properties followed by a * in this document can be controlled by lfos.
Properties followed by a ^ in this document can be inherited from the player or layer settings, and usually are by default.
Player:
The player tab in the lefthand panel defines global settings for the composition.
It has the following user editable properties:
Note settings:
Transpose*
Tempo* (in beats per minute)
Bar Length*
Controls when volume is determined by the emphasis property (first beat of each bar) or the velocity property (all other beats.)
Velocity*
MIDI note velocity. Usually controls the volume of notes.
Emphasis*
Overrides velocity on the first beat of each bar.
Note Length* (in seconds)
Generator settings:
Time to Live*
Number of ticks to wait before automatically deleting playheads.
Pulse Every*
Number of ticks to wait between emitting playheads from generator tokens.
Layer:
Each layer is it's own separate hex grid.
Layers can be used to play multiple instruments, at multiple tempos, or simply to create melodies that don't interact with each other.
The layer controls are located at the top center of the window, from here you can create, delete, and rename layers.
The layer tab in the lefthand panel controls the settings of the currently selected layer.
It contains all of the same properties as the player tab (inherited from the player tab by default) as well as the following:
Enabled
enable or disable the layer
MIDI channel (1-16)
Key
When a key is selected, the notes in that key are highlighted, and note tokens not in the selected key won't play
Playhead:
A red hex that moves across the grid, one hex at a time, each tick.
Playheads are emitted by generator tokens.
A midi note plays when a playhead enters a hex containing a note token.
Playheads have the properties direction and lifespan (number of ticks before deletion)
These properties are not directly editable by the user. instead, they are manipulated by placing tokens.
Tokens:
Tokens create and manipulate playheads.
You can place tokens on the selected hex using the add token button near the top of the righthand panel, or by right clicking on a hex, or with user definable keyboard shortcuts.
You can remove tokens by clicking the red x at the top right of the panel of the desired token, or by right clicking on a hex, or by combining your user defined keyboard shortcuts with the Alt key.
Pressing delete will remove all tokens from the selected hex.
One way that Acheron differs from Elysium is that Acheron allows multiple tokens of the same type on a single hex.
You may also drag and drop tokens from one location on the grid to another (hold shift while dragging to copy)
Users can create their own tokens with json and javascript, for more information see the custom token documentation here:
https://github.com/SongSing/acheron/blob/main/Token_Documentation.md
Acheron currently comes with the following tokens:
Note token:
Plays the midi note of the hex it is located on when entered by a playhead.
It has the following properties, editable in the righthand panel:
Probability*
Controls whether a token runs or is ignored in a probabilistic manner. It's value is the percent chance the token will run.
Triad*
Plays the selected three note chord (relative to the token's hex) instead of a single note.
One of the advantages of the harmonic table layout is that these simple clusters form common chords, the shapes of which are the same in any key.
Transpose*
Gate:
Controls whether a token runs or is ignored in a deterministic manner.
Each time a token is entered by a playhead, the token's internal gate sequence is advanced by one. When the gate sequence reaches the end, it loops.
Gate Off*
Number of times to ignore token. Runs first by default.
Gate On*
Number of times to run token. Runs after gate off by default.
Gate Offset*
Offsets the gate sequence.
For example, if you set gate off to four, gate on to four, and gate offset to two, you get the sequence (on, on, off, off, off, off, on, on)
Velocity*^
MIDI note velocity. Usually controls the volume of notes.
Emphasis*^
Overrides velocity on the first beat of each bar.
Note Length*^ (in seconds)
Ghost Beats*
Not implemented yet
Generate token:
Emits playheads in the chosen direction.
It has the following properties, editable in the righthand panel:
Trigger Mode*
When set to beat, playheads are emitted at the beginning of each period defined by the pulse every property. This is the default.
When set to impact, playheads are emitted when a playhead enters the hex containing the token.
When set to MIDI, playheads are emitted when the user plays the midi note corresponding to the hex containing the token. This is not implemented yet.
Probability*
see the probability section of the note token documentation.
Direction*
Pulse every*^
Number of ticks to wait between emitting playheads.
Offset*
Position in the cycle defined by pulse every at which playheads are emitted.
For example, if pulse every is set to four, and offset is set to one, the following pattern will result, with 0 representing the emission of a playhead: x0xxx0xxx0xxx0xx...
Rebound token:
Changes the direction of any playhead that enters the hex it is located on.
It has the following properties, editable in the righthand panel:
Probability*
see the probability section of the note token documentation.
Direction*
Gate*
See the gate section of the note token documentation.
Skip token:
Moves any playhead that enters it in the direction it's currently going (or the direction of a rebound token on the same hex) by the specified amount.
Supports negative numbers, allowing a playhead to "skip backwards" in the opposite of it's current direction.
It has the following properties, editable in the righthand panel:
Probability*
see the probability section of the note token documentation.
Skip Amount*
Gate*
See the gate section of the note token documentation.
Split token:
When a playhead enters a hex with a split token, a playhead is generated in every direction except the one the initial playhead came from.
Unless Bounceback is turned on, in which case it generates one that way too.
It has the following properties, editable in the righthand panel:
Probability*
see the probability section of the note token documentation.
Gate*
See the gate section of the note token documentation.
Bounceback*
Absorb token:
Deletes any playhead that enters it's hex.
It has the following properties, editable in the righthand panel:
Probability*
see the probability section of the note token documentation.
Gate*
See the gate section of the note token documentation.