Really this is weird but awesome stuff:
“We created a realtime sound-reactive software to visualize the two pieces composed by Dmitri Kourliandski and performed by the Ensemble Intercontemporain.
IRCAM used 24 microphones to get a separated audio signal from each instrument of the ensemble.
Thomas Goepfer created a software which analyzes each signal and extract the sound information; the resulting data are sent to our software and used to animate the elements of the visual composition.”
More info here: http://vimeo.com/15835305