Although he launched his career as a guitarist, accompanying such French poets as Jacques Brel and Ricet Barrier, Clastrier has become increasingly experimental. Introduced to the hurdy-gurdy in 1970, designed and built, with violin-maker Denis Siorat, an electro-acoustic hurdy-gurdy viola with twenty-seven strings rather than the standard six. The instrument's flexibility has enabled Clastrier to explore new musical realms. He collaborated with jazz musicians, Michel Portal and Louis Sclavis on his 1992 album, Heresy. In addition to leading his own group, Clastrier performs with the Michael Riessler Trio, led by the French saxophonist and featuring Carlo Rizzo on tambourine.