code: function (obj, octave) {
    var lastNote = obj.chord[0];
  
    obj.chord = _.map(obj.chord, function (n) {
      // Every time a note is "lower" than the last note, we're in a new octave
      if (n.lowerThan(lastNote)) octave += 1;
  
      // As a side-effect, update the octaves for root and bass
      if (n.enharmonic(obj.root)) {
        obj.root = obj.root.inOctave(octave);
      }
      if (obj.bass && n.enharmonic(obj.bass)) {
        obj.bass = obj.bass.inOctave(octave);
      }
  
      lastNote = n;
      return n.inOctave(octave);
    });
  }
docs: Given a chord object and an octave number, assign appropriate octave numbers to notes