François Bayle

François Bayle (born 1932) is a French composer of acousmatic and musique concrète who directed the Groupe de Recherches Musicales (GRM) in Paris from 1966 to 1997. A student of Messiaen and Stockhausen, he became the principal theorist of acousmatic music — music heard without visible source — developing the concept of the i-son (imaginary sound) as the central figure of electroacoustic composition. He designed and named the Acousmonium, the orchestra of loudspeakers used for spatial diffusion. His output includes the landmark Expérience Acoustique (1969–70), and his theoretical legacy shapes the GRM aesthetic to this day.