Clunky Drummer uses one motor to walk through phased rhythm patterns. It converts them to MIDI via piezo transducers, sending bass, hat and snare signals to a drum machine. This is tweaked along with the effect chain which transforms the sound.
I'm presently cutting together a video of the full installation, documenting the site, ambient sound and audience reaction. This will take a few weeks so I've uploaded this taster footage in the meantime.