Iannis Xenakis
Who Is He?

Xenakis in his studio in Paris in the 1960s. Photo by Françoise Xenakis.

This article was written by Joel Chadabe

Iannis Xenakis is widely recognized as one of the most original and important of the post-World War II composers. Original and important because his music redefines the traditional principles of musical structure. Post-World War II because of the chronology of his career. But there's more to it.

Xenakis had experienced the war. In 1941, he joined the Greek Resistance through the EAM (National Liberation Front). He was imprisoned several times, first by the Italians, then the Germans. In October, 1944, the German army left Greece, and in December, the British army, representing the political right, declared martial law in Athens. Xenakis joined the student battalion of the ELAS (National Popular Army) and became commander of the 'Lord Byron' unit. He was inside a building with two friends when a British tank fired into the building. The explosion shattered his jaw and took out his left eye. In 1945, following several operations, he continued his studies at the Athens Polytechnic Institute while pursuing secretly his political activities. In 1946, despite his fugitive existence, he received a degree in civil engineering. In 1947, as the conservative government gained power, it began hunting and imprisoning former members of the Resistance. In 1947, Xenakis' father was able to get him a forged passport, and in fear for his life, Xenakis left Athens for New York. En route, he arrived in Paris in November 1947. In a conversation that I had with Xenakis in 1994, he told me, "I was a civil engineer—I was on my way to the States, but I stopped in Paris and I thought, 'Well, why not?'"

Le Corbusier, at that time the most celebrated and prestigious architect in France, was based in Paris. Xenakis told me: "I got to Le Corbusier through an acquaintance and I started calculating beams and columns and floors for the Marseilles building." Xenakis was referring to L'Unité d'Habitation in Marseilles, among Le Corbusier's best-known projects. He continued, "After a while I became interested in architecture. So I asked Le Corbusier if I could do an architectural project with him. We started doing the monastery of La Tourette, which I designed completely from beginning to end." Work began in 1954. La Tourette is a three-story Cistercian rectangle of hallways and spaces surrounding an interior courtyard, itself a complexity of passageways and spaces. Note, below, the so-called 'undulating glass panes', panes of different sizes determined by Le Corbusier's Modulor, a scale of measurement based on the Golden Mean.

x_latourette Top to bottom: the entrance; an interior space showing the 'undulating glass panes' and a glimpse of the courtyard; the church; and a view of the Lyonais countryside from La Tourette.

In January 1956, Louis Kalff, an executive at Philips Corporation in Eindhoven, Holland, called Le Corbusier in Paris to invite him to design the Philips Pavilion for the Brussels World's Fair in 1958. Le Corbusier answered: "I shall not create a pavilion, but a poème électronique. Everything will happen inside: sound, light, color, rhythm ... " Xenakis said: "They asked Le Corbusier to design something and Le Corbusier asked me to design something. At that time, I was very much interested in shapes like hyperbolic paraboloids, things like that; and so I organized them to form a shell in which we could produce sounds and images on the walls. I did the designs and I showed them to Le Corbusier and he said, 'Yes, of course.'"


The Philips Pavilion, Brussels World's Fair, 1958

The World's Fair opened in May 1958. The multimedia spectacle in the Philips Pavilion, repeated several times every day, consisted of Xenakis' Concrèt PH, composed with the sound of smoldering charcoal; Edgard Varèse' Poème Electronique, with the sounds of percussion, electronic tone generators, machines, and the human voice played through 400 loudspeakers, mounted in groups to enable 'sound routes' through the space; and colored light forming a background to Le Corbusier's projected images of monkeys, shellfish, birds, and other animals; Buddha, religious scenes from Giotto paintings, and other religious art from different cultures such as masks and sculptures; parts of the Eiffel tower; Laurel and Hardy stills; nuclear explosions and other war imagery; buildings from different countries; and so on... Xenakis felt that the representational imagery chosen by Le Corbusier did not take advantage of the opportunities presented by technology. As he, disapprovingly, summed it up: "It was not abstract." Nonetheless, the architecture and the multimedia spectacle attracted more than two million people during the Fair.

Concrète PH (excerpt)

Edgard Varèse: Poème Electronique (excerpt)

A sampling of images inside the pavilion

Xenakis left Le Corbusier's studio in 1959. He took with him the seminal experience of the Philips Pavilion as a total experience of vision and sound, a total immersive environment in which the space of the images and sounds was integrated with the architectural design. In his polytopes, as he called his spectacles of light and sound, he either designed the spectacle for the space or the space for the spectacle. In 1972, for example, the Polytope de Cluny, with computer-controlled strobe lights, lasers, and sounds, took place in the space of the Roman baths on the Boulevard Saint-Michel in Paris. In 1978, the Diatope, a large red steel-supported tent, its shape reminiscient of the Philips Pavilion, with a translucent glass-panel floor and soft-colored lights below, was designed for a show of 1600 pinpoint lights flashing through the space, four laser projectors forming different shapes, 400 pivoting mirrors and prisms, and the music, known as La Legende d'Eer, coming from everywhere.


The Diatope, Paris, 1978


Shortly after Xenakis settled into his work as a civil engineer with Le Corbusier, he began his music career by looking for someone with whom he could study. After being turned down by Nadia Boulanger, Arthur Honegger, and Darius Milhaud, he followed the advice of Annette Dieudonné, a friend of Nadia Boulanger, who suggested that he seek advice from Olivier Messiaen. Noting Xenakis' background in mathematics and civil engineering, Messiaen advised him not to study harmony and counterpoint but rather to develop his mathematical ideas. Xenakis attended Messiaen's class at the Paris Conservatory regularly through 1952 and less regularly in 1953.

Among many related and various theories and skills, civil engineering articulated for Xenakis the phenomenon of underlying complexity, as found, for example, in a multiplicity of miniscule causalities that are too numerous to be individually traced and, consequently, can be understood only as distributions and probabilities within a statistically-described whole. In 1953, he applied the principle in music by calculating the trajectories of individual stringed instruments, notated as lines rather than notes, in his orchestral composition Metastaseis. It was his first significant composition, and it proved seminal for other ideas and other projects—among them the Philips Pavilion and the UPIC system—throughout his life.

First minute of Metastaseis

In 1956, he coined the term 'stochastic music' to describe music based on probabilities. He told me, "When I was in the Resistance in Athens, there were multiple sounds, many people shouting at the same time, in thousands of cries. And I was amazed by the changes in the sounds. Another thing. I used to go camping around Attica, and I heard the cicadas and the raindrops on my tent, and I was always charmed by these noises."

In his early electronic works, he simulated stochastic music. For Concrèt PH in 1958, for example, he used the sound of smoldering, sputtering charcoal with its very grainy (and stochastic) character. He said: "And then I did Bohor which was done with all sorts of sounds with bracelets. I had some necklaces from Iran. I was interested in the tiny sounds because you could expand them and find different sounds in them."

Excerpt from Bohor

In 1961, some friends in Paris introduced him to IBM-France, and he worked with a computer for the first time. "It was a program using probabilities, and I did some music with it. I was interested in automating what I had done before, mass events like Metastaseis. So I saw the computer as a tool, a machine that could make easier the things I was working with. And I thought perhaps I could discover new things." In 1972, he re-formed an earlier organization to become CEMAMu, a center for research located in Issy les Moulineaux, a suburb of Paris, and began to develop the UPIC system to notate music as shapes instead of notes. In his words, "We are used to seeing things in visual shapes, it's natural." UPIC was finished in 1978. He used it in composing Mycenae Alpha.

Xenakis and UPIC, late 1970s


Mycenae Alpha excerpt, following Xenakis' drawing

In 1978, he demonstrated UPIC at a UNESCO show on art and technology in Paris, and then organized demonstrations throughout France, in Holland, Germany, Portugal, Greece, and Japan, and invited schoolchildren to play with it. He said, "How would you relate probabilities to shapes? Well, look at the clouds."


Demonstrating UPIC, 1979

In later compositions, he extended his concept of stochastic music to computers, and his mathematical substructures to include game theory, Markov chains, group theory, set theory, and various other contexts for working with probabilities. In 1991, at CEMAMu, he began work on the GENDY-N program that generated an audio waveform using a technique that Xenakis referred to as "dynamic stochastic synthesis". I was at CEMAMu in 1994 with Xenakis. He demonstrated the software as a work in process. In the Preface to the Pendragon version of Formalized Music, he wrote: "An important task of the research program at CEMAMu is to develop synthesis through quantified sounds but with up-to-date tools capable of involving autosimilitudes, symmetries or deterministic chaos, or stochastics within a dynamic evolution of amplitude frequency frames where each pixel corresponds to a sound quantum or 'phonon,' as already imagined by Einstein in the 1910s. This research, which I started in 1958 ... can now be pursued with much more powerful and modern means."


Taken by itself, a theory of stochastic music may seem a bit dry. But when Xenakis tells us about it, as in Formalized Music, we feel the pulse of his life and the impact of his wartime experience:

"Everyone has observed the sonic phenomena of a political crowd of dozens or hundreds of thousands of people. The human river shouts a slogan in a uniform rhythm. Then another slogan springs from the head of the demonstration; it spreads towards the tail, replacing the first. A wave of transition thus passes from the head to the tail. The clamor fills the city, and the inhibiting force of voice and rhythm reaches a climax. It is an event of great power and beauty in its ferocity. Then the impact between the demonstrators and the enemy occurs. The perfect rhythm of the last slogan breaks up in a huge cluster of chaotic shouts, which also spreads to the tail. Imagine, in addition, the reports of dozens of machine guns and the whistle of bullets adding their punctuations to this total disorder. The crowd is then rapidly dispersed, and after sonic and visual hell follows a detonating calm, full of dispair, dust, and death. The statistical laws of these events, separated from their political or moral context, are the same as those of the cicadas or the rain ... They are stochastic laws."

With different words, with a different scene, Xenakis' description of a political demonstration, certainly similar to what he experienced in the Resistance in Greece, could describe the process of his music. But with a difference. In his music, Xenakis did not extract the rules from the activity, he used the rules to control his activity, as one might use the mechanics of a steering wheel to drive to the place one wants to be.

His probability calculations are underlying and rarely noticeable. Xenakis personalized his theories. They served him in providing detail and occasionally they led him to places, for better or worse, that no trained musician would go. It is, in a certain sense, paradoxical and interesting to note that although he went far and dug deep to justify his music in mathematical terms, it is the emotional strength in his music, the intuition, passion, and talent—in other words, traditional values—that win the day.


This article was first published in January 2010 in Arts Electric, an online publication of Electronic Music Foundation, in connection with a series of concerts of Xenakis' music produced by Electronic Music Foundation during the spring of 2010.