That's galapagoose jamming with the left hand drumming out the beat on a pad controller and the right hand dealing with the rest of the music sequenced in real-time on a grid controller called the monome. The samples used for the performance come from a connected computer and are simply mapped onto the controllers for live use. I think it's cool.

Another example here of Imogen Heap using the monome as accompaniment:

Massively talented live trio made up of a saxophonist, a cellist and a beat maker who go by the name of Archie Pelago.