Mutable surface: inter-routing improvisation using Max/MSP and NATO “or” 14 theaters taken from a certain Chinese encyclopedia. Gremo and Beekman have created a multiple computer “route” on which they improvise with concrete and synthetic audio and projected video using many digital processing strategies controlled by shakuhachi, flute, electronic wind instrument and Wacom tablet. The theme could be: computer video as musical instrument or how to play the surface of a sound.