A drummer volunteered to help out a Georgia Institute of Technology project involving a robotic arm. From CNET:
The arm plays with a laudable amount of subtlety. It pays attention to the drummer, switching between the ride cymbal and the floor tom depending on which other parts of the drum the musician is using. It changes tempo in response to the drummer speeding up or slowing down.
Built-in accelerometers and motors help keep the robo-arm in position and on beat. The builders programmed the arm using motion-capture technology to give it human-like movements.
Got it? Now watch.