This is a demonstration of 12Step - a sequencer with a "novel musical interface", developed by Ted Hayes at the Interactive Telecommunications Program (ITP) for New Instruments for Musical Expression (NIME).
Software used: Puredata 0.41.4-extended, Ableton Live 8, Native Instruments Akoustik Piano.
The video demonstrates mode changes, weight randomization and multiple concurrent sequences.
Link:More From: EXPERIMENTAL MUSIC
And how the Ladder filter sound was made in error...