Fingers slipping over guitar strings, the tap of a bow against the body of a cello, a pianist humming along to the music: contemporary composers often work with parasitic, non-conventional sounds such as these. Are they to be perceived as musical elements or do they shift attention to the physical effort of music-making, contact between a body and an instrument? Composer Paul Craenen explores ways in which the musician's body is revealed in musical performance. He leads us from Cage, Lachenmann, Kagel, and their contemporaries to a discussion of how today's generation of young composers is...