code: function (notes, settings) {
    var noteEvents = makeNoteEvents(notes, settings);
    var setPatch = makePatchEvent(0, settings.melodyPatch);
    var length = setPatch.length + noteEvents.length + trackFooter.length;
  
    return Buffer.concat([trackHeader, padNumber(length, 4), setPatch, noteEvents, trackFooter]);
  }
docs: Return a buffer with a melody track