An intimidating drawing, but the basic principle is simple: the sketch is a graph with time on the horizontal axis (the vertical lines represent measure numbers) and pitch on the vertical axis (the horizontal lines correspond to the pitch-class E in various octaves). Xenakis's goal is to replicate the curved lines of the Philips Pavilion in musical form. Just like you did in high school physics class, Xenakis has taken tangents to the curve at various points; each tangent represents a solo string instrument, playing a glissando.
Relatively straightforward, right?
Except I lied to you; the above is not an excerpt from the score, but a sketch that the composer made during composition. The conductor's score, and the player's parts, are conventionally notated. Yet every history of twentieth-century music prints this sketch as an example of Xenakis's "mathematical composition", giving the readers the impression that Xenakis scores are Cartesian plots requiring special training to interpret. This little factoid is the only thing most musicians will ever learn about Xenakis, and it's wrong. Sigh.
Xenakis had a tough life. During the Second World War he fought in the Greek Resistance, a sort of guerrilla wing of the Communist party which sought to overthrow the occupying Nazis. Upon repelling the Nazis, the country was thrown into civil war between right-wing and Communist political factions - with the American and British governments providing support to the rightist factions. During the conflict, Xenakis lost most of the left side of his face to an enemy shell, and fled the country just in time to avoid being sentenced to death by the new right-wing government. Upon arriving in Europe, he found himself in the middle of yet another ideological conflict; conservative composers like Arthur Honegger balked at his modernist style, while Boulez and the other Darmstadt serialists considered his music "too simple".
Yet Xenakis managed to produce some of the most interesting and characteristic music of the twentieth century. In conversation with Bálint András Varga, he comes across as a lively figure with an disarming sense of humour, and good taste in instruments:
Do you have a preference for any particular instrument?Later in the conversation, Varga asks him to explain the purpose of three of the unusual objects in his studio: a ladder, a knotted rope tied to the ceiling, and a tall, oversized music stand. Xenakis explains that the music stand is to compose; he works standing up because of his bad back. The knotted rope is an "eternal challenge" - he had originally intended use it to climb up to the ceiling, but has given up on this idea. The ladder is so that Xenakis can clean the curtains.
I like the organ but I have a particular flair for string instruments. The only instrument I don't like is the flute - it has a silly sound. [. . .]
The dynamic level of your music still favours f to fff.
That's because I'm growing more deaf.
Do you really mean that?