So there's this guy Levy Lorenzo. He's a percussionist and I'm pretty sure that this is him playing with his band 'The Teapot Dome Orchestra'. He is (or was) a student at Cornell, studying MIDI, so he decided to build a Hamster controlled MIDI sequencer. It's three note polyphonic. Each channel is controlled by two hamsters, one for the melody, one for the rhythm. The output (through a Boss Dr Synth) sounds like this. Genius!
Project Page.