I saw a really interesting presentation by Vibeke Sorensen, Miller
Puckette and Rand Steiger at the Intel campus in Hillsboro, Oregon
recently.

Their project is called the Global Music Jam, and you can check it out
online at http://www.visualmusic.org:

"Global Visual-Music Jam Project Networked multi-media computing has
made it possible to bring together musicians and artists at locations
throughout the world as a virtual ensemble, available to audiences in
distributed locations. Through analysis of musical and physical
gestures, performers can interact with graphics and animation in real
time, giving rise to a real-time visual music performance that can be
web cast. The software environments necessary to realize this integrate
networked computing, 2 and 3D computer graphics, video and audio signal
processing and computer music. We will be discussing and showing
examples of these software environments, named Pd and GEM, as well as
our public Global Visual Music experiments and performances to date."