A couple of years ago I started getting into Picaxe microcontrollers, and I ordered a bunch of random components to experiment with. Turning these funny little spring-mounted motors on and off, I thought, Hmm — I could put a stick on that and let the microcontroller drum! This mini sound-recorder board? Hey, if the robot is drumming, it could record itself and play a new beat with the first one in a loop. Oh, nice yellow tracks, a rangefinder — cool, it could move around and look for things to drum on.