random-chord-progressions.js

const _ = require('lodash');
const scribble = require('scribbletune');
const setOfNotes = scribble
  .scale('C3 lydian')
  .concat(scribble.scale('C4 lydian')); // or simply scribble.scale('C3 major') OR manually set the notes
const pattern = 'x__[xx]x_x_'.repeat(8); // or a simple one 'x___'.repeat(4)
const count = pattern.replace(/[^x]/g, '').length;
const notes = [];

for (let i = 0; i < count; i++) {
  notes.push(_.sampleSize([...setOfNotes], 3));
}

scribble.midi(
  scribble.clip({
    notes,
    pattern,
  })
);

// This will generate a file called music.mid at the same location as this script is run.