MIDI controlled Glockenspiel I'm using an Arduino Diecimila board to receive MIDI signals and driving solenoids arranged to strike the bars on a child's toy Glockenspiel. Full details, schematic, code, photos and video are on :- http://www.thebox.myzen.co.uk/Hardware/Projects.html
I used Garage Band with the plug in MidiO to drive it to play some Phillip Glass music. As it doesn't move very much while it plays I used some animated stills over the sound track.
There is also details on how to make your own Arduino shield from strip board.