code: function (deltaTime, on, firstChannel, chord, velocity) {
    var arr = [];
  
    // Make note event for first note after appropriate time
    arr.push(makeNoteEvent(deltaTime, on, firstChannel, noteValue(_.first(chord)), velocity));
  
    // Make note event for rest of the notes
    _.each(_.rest(chord), function (note, i) {
      arr.push(makeNoteEvent(0, on, i + firstChannel, noteValue(note), velocity));
    });
  
    return Buffer.concat(arr);
  }
docs: Make a multiple MIDI note events for a given chord