strudel/packages/midi/README.md

@strudel/midi

This package adds midi functionality to strudel Patterns.

Install

npm i @strudel/midi --save

Available Controls

The following MIDI controls are available:

• note - Sends MIDI note messages. Can accept note names (e.g. "c4") or MIDI note numbers (0-127)
• midichan - Sets the MIDI channel (1-16, defaults to 1)
• velocity - Sets note velocity (0-1, defaults to 0.9)
• gain - Modifies velocity by multiplying with it (0-1, defaults to 1)
• ccn - Sets MIDI CC controller number (0-127)
• ccv - Sets MIDI CC value (0-1)
• pc - Sends MIDI program change messages (0-127)
• sysex - Sends MIDI System Exclusive messages (array of bytes 0-255)

Additional controls can be mapped using the mapping object passed to .midi():

Examples

midi(outputName?)

Either connect a midi device or use the IAC Driver (Mac) or Midi Through Port (Linux) for internal midi messages. If no outputName is given, it uses the first midi output it finds.

$: chord("<C^7 A7 Dm7 G7>").voicing().midi()

In the console, you will see a log of the available MIDI devices as soon as you run the code, e.g. Midi connected! Using "Midi Through Port-0".

midichan(number)

Selects the MIDI channel to use. If not used, .midi will use channel 1 by default.

ccn && ccv

• ccn sets the cc number. Depends on your synths midi mapping
• ccv sets the cc value. normalized from 0 to 1.

$: note("c a f e").ccn(74).ccv(sine.slow(4)).midi()

In the above snippet, ccn is set to 74, which is the filter cutoff for many synths. ccv is controlled by a saw pattern. Having everything in one pattern, the ccv pattern will be aligned to the note pattern, because the structure comes from the left by default. But you can also control cc messages separately like this:

$: note("c a f e").midi()
$: ccv(sine.segment(16).slow(4)).ccn(74).midi()

pc (Program Change)

The pc control sends MIDI program change messages to switch between different presets/patches on your MIDI device. Program change values should be numbers between 0 and 127.

// Play notes while changing programs
note("c3 e3 g3").pc("<0 1 2>").midi()

Program change messages are useful for switching between different instrument sounds or presets during a performance. The exact sound that each program number maps to depends on your MIDI device's configuration.

sysex (System Exclusive Message)

The sysex control sends MIDI System Exclusive (SysEx) messages to your MIDI device. sysEx messages are device-specific commands that allow deeper control over synthesizer parameters. The value should be an array of numbers between 0-255 representing the SysEx data bytes.

// Send a simple SysEx message
let id = 0x43; //Yamaha
//let id = "0x00:0x20:0x32"; //Behringer ID can be an array of numbers

let data = "0x79:0x09:0x11:0x0A:0x00:0x00"; // Set NSX-39 voice to say "Aa"

note("c d e f e d c").sysex(id, data).midi();

The exact format of SysEx messages depends on your MIDI device's specification. Consult your device's MIDI implementation guide for details on supported SysEx messages.