I think I've seen that one. I also like this presentation by extempore's author [1]. It is pretty cool in that it shows how to model instruments out of simple waves and "attack, decay, sustain and release" envelope modeling. Pretty quickly he comes up with something that kind of starts sounding like real instruments (squinting a bit... :-).

1: https://www.youtube.com/watch?v=phYHOUICe7Q