Giannis Klearchou Xenakis (also spelled for professional purposes as Yannis or Iannis Xenakis; Greek: Γιάννης "Ιωάννης" Κλέαρχου Ξενάκης; 29 May 1922 – 4 February 2001) was a Romanian-born Greek-French avant-garde composer, music theorist, architect, performance director and engineer. After 1947, he fled Greece, becoming a naturalised citizen of France eighteen years later. Xenakis pioneered the use of mathematical models in music such as applications of set theory, stochastic processes and gam ...