https://github.com/generative-music/pieces-alex-bainter/blob/master/packages/piece-observable-streams/src/piece.js https://github.com/generative-music/pieces-al

https://github.com/generative-music/pieces-alex-bainter/blob/master/packages/piece-observable-streams/src/piece.js https://github.com/generative-music/pieces-alex-bainter/blob... Difficulty? hard to say, looks like knowledge of the various libs used is pretty critical, but pieces look to be between 100-200 lines.