"SoundMachine is a 4 track 8-step drum sequencer that uses the LEGO Mindstorms NXT to scan a set of drum "notes" which are then played using Ableton Live. The NXT uses four colour sensors to detect the colour of 2x2 LEGO bricks as the plate is scanned in. A controller written in Processing interprets the colour pattern and sequences MIDI note messages to send to Ableton Live, which in turn plays the sounds you hear.
The music on the video was created by SoundMachine itself - music you can build"
This video shows how the plate is scanned and converted into notes in the GUI, which in turn sends MIDI commands to Ableton Live to play the music.
Fantastic creation by Markclego