IN C, composed in 1964 by Terry Riley, is a hit of American minimalist music. Bagpiper, composer and improviser Erwan Keravec has seized upon it, bringing together twenty musicians, bagpipers and bombard players. This unheard-of version of the work in continuous breath and supersonic drone is an experience made all the more gripping by the fact that the audience takes its place at the heart of the musicians arranged in a circle on podiums.