Jamocracy

This could be an iPad app that shows up as an instrument that enables many-person low-entry-barrier jams by having a standard metronome and responding to variation from the metronome beat with adaptively corrected modulation of the audio output. So, if you get off beat the system changes your sound so that it is more mushy, or so that it doesn't have a sharp attack and release. Your sound would only gain a sharp attack / release if you are consistently on beat, and you would be "punished" for varying from the beat with a slow attack sound that is adaptively coordinated with the other sounds in the jam.