Create a commonly used dance music riff using just Scribbletune

riff.js

const scribble = require('scribbletune');

const getRandomPattern = function(count = 8) {
  let str = '[x-]R';
  for (let i = 1; i < count; i++) {
    str += Math.round(Math.random()) ? '[x-]R' : 'R[x-]';
  }

  return str;
};

const pattern = getRandomPattern();

const clipA = scribble.clip({
  notes: 'D2',
  randomNotes: scribble.arp(
    scribble.getChordsByProgression('D2 minor', 'ii iii')
  ),
  pattern,
  subdiv: '16n',
});

const clipB = scribble.clip({
  notes: 'D2',
  randomNotes: scribble.arp(
    scribble.getChordsByProgression('D2 minor', 'iii v')
  ),
  pattern,
  subdiv: '16n',
});

scribble.midi([].concat(clipA, clipA, clipA, clipB), 'riff.mid');