Yeah, I don't see how it could be done.. unless all the players got optic fiber or something, and even so I'm not sure. I would be very interested in a collaborative sequencer though. Let's say drummer record a first loop, then everyone can hear it, guitarist plays a chord progression over it and record it, then the singer can add his part. The drummer then decides to add a special part at some place to go together with the singer and he edits his sequence so it's not 100% loop anymore, etc etc...