Pop is an experiment in using a midi keyboard controller to capture motion data in 3DS Max. Certainly not a new concept (Animusic has been doing it since the 90's), but it's one Michael wanted to explore. He rigged the keys of the 3D piano to respond to the corresponding keys on the controller. Then he routed that same midi data to Propellerhead's Reason to create the musical score. The end result was a perfectly synced, 3D keyboard performance. He then hand-keyframed the robots to follow the piano.