IANNIS XENAKIS was born to Greek parents living in Romania in 1922. His childhood interests included the rich folk music of his native region as well as mathematics and engineering, which led him to enter Athens Polytechnic with the intention of becoming an engineer. He began to seriously pursue music during this period.

When World War II broke out, Xenakis joined the Resistance movement and eventually moved to Paris. It was here that his complementary interests - engineering and music - led to an encounter with architect Le Corbusier, who introduced him to two leading members of the musical avant-garde, Varèse and Messaien. It was with these early contacts in France that the self-taught musician was able to find encouragement, support and the help he needed to publish an article and conduct several premières. He even completed a formal music degree under Messaien at Sorbonne. Xenakis' acquaintance with Le Coursier enabled him to undertake some engineering calculations and collaborate with the architect on several studies for housing projects in Nantes and Marseilles, the convent of La Tourette, the assembly building at Chandigarh, and the Baghdad stadium. He invented an architecture constructed entirely from faces derived from the hyperbolic paraboloid for the Philips Pavilion at the 1958 Brussels Exposition.

This was an architectural revolution that was closely associated to the composer's breakthrough work and first composition, Metastasis, in which he unified architectural space and music. His obsession with "space" permeates his pieces most directly concerned with sound, and the connections between the two are elaborated in his works. It is the use of mathematical processes that allow Xenakis to discover patterns and communicable musical ideas out of a totally unrestricted musical vocabulary. His compositions arise from more abstract structures and mathematical models, recalling Greek mathematical philosophy.

Metastasis (1953-4) and Pithoprakta (1955-6), another orchestra piece concerned with global, mass phenomena, were followed by the first product of Xenakis work in the Groupe de Recherches Musicales: Diamorphoses (1957-8). His use of set theory in musical composition is exemplified by Herma for piano (1960-4). His music also reflects an interest both in electronic music and in Greek culture, especially folk culture and ancient Greek drama.

To stimulate research into music theory, he founded the Equipe de Mathematique et d'Automatique Musicales (EMAMu) in Paris in 1966. In the years following he toured the globe attending performances of his music, lecturing and giving courses in composition and aesthetics. He taught for several months of each year at Indiana University, Bloomington from 1967 to 1972, where he founded a sister branch to the EMAMu: the Center for Musical Mathematics and Automation. In 1970, the EMAMu was granted official recognition by the French government and accommodation in the Centre de Recherche Nucléaire of the Collège de France.