Show HN: annotated drum machine for the Novation Launchpad, in Chuck

a musician friend of mine is interested in learning a bit about programming, so I wrote a simple drum machine and annotated the source. The drum machine itself is designed for the Novation Launchpad, so it can't be played without the proper device. That's probably going to severely limit the audience, but I figure it's still worth sharing on HN, so that people can see a bit of what Chuck looks like, for simple things.