A few things that can be added to make this more fun and functional:
- Disable all clickables when playback has started
- Make the "play" button into a "stop" button while playing
- Re-animate each part as its played back
- Display volume as a numerical value
- Display speed as BPM (beats per minute)
- Show the current note queue
- Allow dragging the notes to change the order
- Allow deleting notes from history if we make a mistake
- Create multiple layers of sound so two can play at once
- Perhaps could also assign the notes to a time signature as well
- Can custom add notes to any spot on the playback grid
- Add keyboard button functionality to play each drum part
- Add a second symbol to the high-hat and use a keyboard button to close it, playing a different sound