(1922–2001)
Composer, architect, and engineer, he was born in Brăila (Romania) of Greek parents. During World War II he joined the Greek Resistance. He completed his studies at the Athens Polytechnic. Sentenced to death following a political trial, he emigrated to France in 1947, becoming a French citizen in 1956. He studied music with Hermann Scherchen in Gravesano and Olivier Messiaen in Paris, and served as assistant to Le Corbusier. In 1976 he received a doctorate in literature and the humanities from the Université de Paris I (the Sorbonne).

The creator of stochastic and symbolic music, Xenakis introduced into his compositions (instrumental, electronic, and computer-assisted) innovations based on probability calculus and mass theory. He produced a series of light and sound compositions, which he called “polytopes.” His innovative techniques quickly became the lingua franca of the musical avant-garde.

In the field of architecture, he designed the Philips Pavilion at the World Fair in Brussels (1958), the Couvent de la Tourette (1955), and many other structures. For the French pavilion at the 1967 Montreal Expo, he created the Polytope de Montréal: an audiovisual spectacle of sculpture, light and sound with music scored for four orchestras. In 1971 he created another “polytope” in the ruins of Persepolis (Iran), and in 1978 the Polytope de Mycènes in the ancient ruins of Mycenae in Greece. In the same year his Diatope added splendour to the inauguration of the Centre Pompidou in Paris. 

Xenakis was the founder (1966) and director of the Centre d’Études de Mathématique et Automatique Musicales (CEMAMu) in Paris, founding a similar research centre, Center of Mathematical and Automated Music, at the University of Indiana in Bloomington where he was an associate professor from 1972. In 1970–72 he was a member of the Centre National de la Recherche Scientifique. He was also a professor at the Sorbonne University (professor emeritus from 1990). His memberships included the American Academy and Institute of Arts and Letters (1975), the French Institute (1983), and numerous other academies and universities. He received honorary citizenships and medals from French, Romanian, and Greek cities (including Mycenae in 1978), the Grand Prix National de la Musique in 1976, and the Beethoven Prize of the City of Bonn in 1977. He was made a Knight of the Legion d’Honneur in 1982, followed by Officer of the Ordre National du Mérite (1985), Officer of the Legion d’Honneur, Commander of the Ordre des Arts et des Lettres (1991), and Commander of the Ordre National du Mérite (1995). He was also awarded the Kyoto Prize in 1997, the International Music Council Award in 1998, and Polar Music Prize from the Royal Swedish Academy of Music in 1999. Publications: Musiques formelles (Paris, 1963), Musique. Architecture (Tournai, 1971), Formalized Music (London, 1971), Arts/Sciences. Alliages (Paris, 1979), Xenakis: Les Polytopes (with Olivier Revault d’Allonnes, Paris, 1975). 

Selected works (from 1975): Phlegra for 11 winds (1975), Retours-Windungen for 12 cellos (1976), Mikka-S for violin (1976), Kottos for cello (1976), Jonchaies for orchestra (1977), Khoaï for harpsichord (1976), La légende d’Eer for 1600 ashlights, laser beams, 400 mirrors and 7-track tape (1977), Pléïades for six percussionists (1978), Aïs for baritone, percussion and orchestra (1980), Nekuïa for mixed choir and orchestra (1981), Mists for piano (1981), Serment-Orkos for a cappella choir (1981), Komboï for harpsichord and percussion (1981), Pour les baleines for string orchestra (1983), Pour la paix for mixed choir, tape and narrators (1982), Shaar for string orchestra (1983), Tetras for string quartet (1983), Chants des soleils for mixed choir, children’s choir, brass and percussion (1983), Khal Perr for brass quintet and percussion (1983), Naama for harpsichord (1984), Lichens I for orchestra (1984), Idmen A for mixed choir and four percussionists (1985), Idmen B for six percussionists (1985), À l’Île de Gorée for amplified harpsichord and ensemble (1986), Keqrops for piano and orchestra (1986), Keren for trombone (1986), Horos for orchestra (1986), Jalons for 15 instruments (1986), XAS for saxophone quartet (1987), Kassandra for baritone, psaltery and percussion (1987), Tracées for large orchestra (1987), À R. (Hommageà Ravel) for piano (1987), Waarg for 13 instruments (1988), Rebonds for percussion (1988), Échange for bass clarinet and 13 instruments (1989),Voyage absolu des Unari vers Andromède for tape (1989), Epicycle for cello ensemble (1989), Tetora for string quartet (1990), Knephas for 32 mixed voices (1990), Kyania for orchestra (1990), Tuorakemsu for orchestra (1990), Roáï for orchestra (1991), Troorkh for trombone and orchestra (1991), Krinoïdi for orchestra (1991), Les Bacchantes d’Euripide for female choir and ensemble (1993), Mosaïques for orchestra (1993), Dämmerschein for orchestra (1993–94), Mnamas Xapis to Witold Lutosławski for two trumpets and two horns (1994), Sea Nymphs for mixed choir (1994), Koïranoï for orchestra (1994), S. 709 for tape (1994), Ergma for string quartet (1994), Ioolkos for orchestra (1995), Kuïlenn for nine winds (1995), Ittidra for string sextet (1995), Roscobeck for cello and double bass (1996), Sea-Change for orchestra (1997), Zythos for trombone and six percussionists (1996), O-Mega for percussion and 13 instruments (1997).