Composer and musicologist, born in Sofia, Bulgaria, who took French nationality in 1955. He studied at the Sofia Conservatoire, then went to Paris (1949) and attended the Ecole Normale de Musique (1949-51). He composed chamber music and a sonata for piano (1959-60). His Musique a trois played in the Domaine Musical led him to work with Berio and Maderna (Milan), and he produced an opera Le nom d'Oedipe by Hélène Cixous (1978). A music critic, he was interested in serial and aleatoric music, and published an edition of Stravinsky (1987), and texts on Schumann (1956), Chopin (1962), and Beethoven (1963).