Iannis Xenakis (1922-2001, Greece/France), although he was born in Romania, in the age of five he settled with his family in Greece. In 1947 he began his studies at the Athens Polytechnic Institute, where he was also part of an anti-fascist and later anti-English underground movement. Because of these activities he was sentenced to death in 1947. The same year he fled to France where he started working as an architect, an assistant of Le Corbusier until 1960. In these years he realized among other things the Monastery of La Tourette (Couvent de La Tourette, 1955), and the Philips Pavilion at Expo in Brussels (1958).

His first musical studies were in 1948 with Arthur Honegger, Nadia Boulanger and Darius Milhaud. In 1949-1950 he studied with Olivier Massiaen, who encouraged him to develop his creative musical ideas. Xenakis’s first success in music was the premiere of Metastasis at the Donaueschingen Festival in 1955. At the time when serialism was the dominating technique Xenakis ventured on a new path, owing to his knowledge of design and engineering (he introduced the probability theory into composing technique), and to his interest in complex acoustic phenomena. In his large oeuvre an important place belongs to electroacoustic and multimedia works which include sound, light, movement and architecture. In the domain of computer music he was the pioneer of algorithmic composition. He devised a system of digital synthesis and the random variation of waveforms.

In 1965 Xenakis founded the Centre d’études de mathématiques et automatique musicales (CEMAMu) in Paris. He was a professor of music at several universities: Center for Mathematical Automated Music (CMAM), and also its founder, at the Indiana University in Bloomington (1967–1972); Sorbonne University in Paris (1972-1989); the City University of London (1975).

Xenakis received many awards and titles such as the Manos Hadjidakis Prize in Athens (1963), Nippon Academy Award (1971), Officier de l’Ordre National du Merite in Paris (1985).

Xenakis enjoyed a long and fruitful relationship with the London Sinfonietta. He composed Phlegra for the ensemble in 1975, and completed his fourth commission for them in 1997 with O-Mega. Waarg (1988) was a follow-up to the highly successful Thalleïn, premiered in 1985. While the earlier piece is characterized by a particular brilliance, Waarg is dense and rather sombre; the title itself means “work“, perhaps an indication of its serious tone. While certainly challenging from a technical standpoint, Waarg is more orchestral than chamber-like, indicating an aesthetic shift in the years following Thalleïn.

Waarg‘s opening features winds in a sustained expansion from a single pitch to a chord. The emphasis on tone color is striking as the central note is passed from one instrument to another. The focus thereafter is on harmonic color, though instrumental timbre continues to play a role as Xenakis often treats the woodwind, brass, and string instruments as distinct entities. Xenakis sculpts and orchestrates the sonorities with great subtlety, fleshing out melodic passages with the addition of close-voiced parallel harmonies or clusters. The tempo is generally quite slow, but ostinato figures, often comprised of just two notes, provide rhythmic propulsion.

Waarg takes shape in a quite fluid manner, various strands of material flowing over, under, and into one other. Gradually, the activity accumulates, with more and more frequent intrusions of faster elements. At Waarg‘s high point, there is an extraordinary passage in which each instrument pursues its own intricate path, creating a brisk contrapuntal texture of great density. A slow and chorale-like — though fitful — section for woodwinds and strings brings the work to a close.
~ All Music Guide