Italian sound designer and producer Guiseppe Acito constructed a band from Lego Bionicle toys driven by an Arduino Uno and controlled by an iPad MIDI sequencer app called Nord Beat.
Dubbed the Toa Mata Band, the musical group makes its tunes by beating on assorted drum pads, percussion instruments, synthesizers and even a Nintendo DS. Acito has published 2 videos of this band.
The toys robots band playing live some tiny synthetizer and each member is controlled by an Arduino Uno which is hooked up to an iPad running a MIDI sequencer app.
Have fun with these 2 videos.
The instruments used in the second video are: Gakken SX 150 and SX 150 MKII, Dubreq Stylophone, Amdek PCK 100, Nintendo DS with Korg DS10 cartridge.
Arduino also controls the RGB LED WALL in the back.