classical inheritance now uses Object.create instead of new
new pattern for Note constructor
NoteSounds construction now follows the new pattern
NoteCollection doesn't implement a size variable now, it uses the length of the array instead
Chord now used the new construction pattern
Chord.invert() now uses rotate() and rotateBack() methods from NoteCollection
ChordCollection now used the new constructor pattern
Eliminated size instance variable from ChordCollection, getSize now uses chords.length
ChordCollection.toString now uses this.getSize()