This project generates polyrhythms from a set of pitches, with support for microtonal notes. It's designed to produce MIDI similar to what I imagine was used to produce videos like this.
This project also serves as an example of working with and extending @perry-rylance/midi.
Run npm install.
Run npm run dev.
Parameters are hard coded in Generator.ts, feel free to change them however you like.
To generate the MIDI file, run tsc && node ./dist/index.js.