French composer and music theorist of Greek background; b. Brăila, Romania (of Greek parents), May 29, 1922. At the age of 10, Xenakis was taken by his family to Greece, where he began to study engineering. His schooling was interrupted when he became involved in the Greek resistance movement against the Nazi occupation forces. He was severely wounded in a skirmish in 1945 and lost sight in one eye. Shortly thereafter he was captured, but he managed to escape to the U.S.

In 1947 Xenakis went to Paris and later became a naturalized French citizen. He studied architecture with Le Corbusier and became his assistant from 1948 to 1960. During the same period he took lessons in composition with Heinz Honegger and DARIUS MILHAUD at the École Normale de Musique in Paris and with OLIVIER MESSIAEN at the Paris Conservatory from 1950 to 1953.

He aided Le Corbusier in the design of the Philips Pavillion at the 1958 World's Fair in Brussels, where he met EDGARD VARÈ SE, who was then working on his Poème electronique for the exhibit. He assisted Varèse, and in return received stimulating advice on the creative potential of the electronic medium.

During his entire career, Xenakis strove to connect mathematical concepts with the organization of a musical composition, using the theory of sets, symbolic logic, and calculus. Unlike chance music, Xenakis's compositions have an internal logic, although it may be difficult for the listener to hear. He published a comprehensive volume dealing with these procedures, Musiques formelles (Paris, 1963; English translation, 1971, as Formalized Music; second edition, revised, 1992).

Xenakis was founder-director of the Centre d'Études Mathématiques et Automatiques Musicales in Paris in 1966, and founder and director of the Center for Mathematical and Automated Music at Indiana University in the U.S., where he served on the faculty from 1967 to 1972. From 1972 to 1974 he was associated with the Centre National de la Recherche Scientifique in Paris. He was a professor at the University of Paris from 1972 to 1989.

In 1974 Xenakis received the Ravel Medal of France, and in 1975 he was elected an honorary member of the American Academy of Arts and Letters. He received the Grand Prix National de la Musique of France in 1976, and in 1983 he was made a member of the Académie des Beauxarts of France. In 1987 he received the Grand Prix for music of Paris.

Xenakis's influence on the development of advanced composition in Europe and America is considerable, and several composers have adopted his theories. Xenakis uses Greek words for the titles of virtually all of his works to stress the philosophical derivation of modern science and modern arts from classical Greek concepts. In some cases he uses computer symbols. His use of the computer led him to develop the computer drawing board, UPIC, which he used for both compositional and educational purposes.

Among his many works are:

Metastasis for 61 instruments (a harbinger of KRZYSZTOF PENDERECKI'S cluster pieces; 1953-54)

Duel, musical game for two "antagonistic" conductors and two orchestras playing different material, mathematically based on game theory, with the audience determining the winning orchestra (1959)

ST/48-1,240162 (1956-62; ST=stochastic; 48=number of players; 1= first work for this contingent; 240162 = 24 January 1962, date on which the work was finally calculated by the IBM 7090 computer in Paris as programmed by Xenakis)

ST/10-1,080262 (1956-62; a string quartet version is entitled ST/4)

Atrées for 10 players (1956-62; written in homage to Blaise Pascal and calculated by the IBM 7090)

Strategie, musical game for two conductors and two orchestras (1959-62; Venice Festival, 1963; Bruno Maderna's orchestra won over that of Konstantin Simonovic)

Polla ta dhina (Many Are the Wonders) for children's choir and small orchestra, to a text from Sophocles's Antigone (1962)

Eonta (Ionian neuter plural of the present participle of the verb "to be"; the title is in Cypriot syllabic characters of Creto-Mycenean origin) for piano, two trumpets, and three tenor trombones (1963-64)

Terretektorh for 88 players scattered among the audience (1966)

Hibiki-Hana-Ma, 12-channel electroacoustic music distributed kinematically over 800 loudspeakers, for the Osaka EXPO 70 (1969 -70 ; also a four-channel version)

Persepolis, light-and-sound spectacle with eightor fourchannel electroacoustic music (1971)

Retours—Windungen for 12 cellists (1976)

Chant des soleik for chorus, children's chorus, winds, and percussion (1983)

Tracées fot orchestra (1988)

Sea Nymphs for chorus (1994)

Xenakis also composed many works for solo instruments and a variety of tape pieces.