July: Xenakis publishes "La crise de la musique sérielle" (The crisis of serial music) in the first issue of the Gravesaner Blätter. This text most likely corresponds to a lecture he gave at the symposium organized by Hermann Scherchen in Gravesano between July 24 - 31 on the subject "Was ist leichte Musik?"
In this article, Xenakis denounces the very principle of the series and the polyphonic organization that is derived from it.
"[…] the serial system is thrown into question on its own two bases, which embody the seed of their own destruction and inadequacy:
their polyphonic structure.
A series (of any sort) is the result of a linear "category" of thought. It is a string of a finite number of objects. […]
Combinatory calculus is but one generalization of the serial principle. Its origin is found in the choice of how the 12 tones are arranged. […]
Linear polyphony is self-destructive in its current complexity. In reality, what one hears is a bunch of notes in various registers. The enormous complexity prevents one from following the tangled lines and its macroscopic effect is one of unreasonable and gratuitous dispersion of sounds over the whole sound spectrum. Consequently, there is a contradiction between the linear polyphonic system and the audible result, which is a surface, a mass.
This inherent contradiction with polyphony will disappear only once sounds become totally independent. In fact, since these linear combinations and their polyphonic superpositions are no longer workable, what will count will be the statistical average of isolated states of the components’ transformations at any given moment. […] Hence, the notion of probability is introduced, which, by the way, implies combinatory calculus in this specific case." ("La crise de la musique sérielle", from Kéleütha. Ecrits, L’Arche, Paris, 1994, p.40-42, previously unpublished in English).
October 15: première of Metastasis at the Donaueschingen Festival by the Südwestfunk Orchestra, conducted by Hans Rosbaud. An outright scandal in these hallowed halls of serialism.
"I was banned for many years from all German musical avant-garde activities; however, later on, it was there that I started being well-known. […]" ("Entretien avec Mario Bois", Bulletin d’information, n° 23, Boosey & Hawkes, 1966, p.4)
Xenakis joins Pierre Schaeffer’s Groupe de recherches de musique concrète (that becomes the GRM or Groupe de recherches musicales in 1958) and remains until 1962. The first work he does there is Diamorphoses.
May 16: birth of his daughter, Mâkhi Zyïa.
July: publication of his " Probability theory and musical composition" in the Gravesano Blätter, n° 6, which is later reprinted in his book, Musiques Formelles (La Revue Musicale, n° 253-254, Richard-Masse, Paris, as well as in the English translations, Formalized Music cf. under Works, then Books). There, Xenakis explains the stochastic laws used in Pithoprakta, which he was composing at the time.
In Le Corbusier’s Studio, Xenakis collaborates on the Youth and Cultural Center in Firminy. In October, he begins working on the plans of the Pavilion that Philips commissioned Le Corbusier to create for the Brussels World Fair in 1958 and that the latter simply projected as being "a free-form hollow structure." Inside, images and lights were to be projected and a spatialized electroacoustic work were to be proposed to the visitors/spectators. Le Corbusier had imposed Varèse to Philips to realize the music of this Electronic Poem.
"It was a unique opportunity for me to imagine an edifice, both in its structure and form, constructed exclusively of hyperbolic parabola (or P.H., in French) and conoids, and especially, self-supporting." (Iannis Xenakis, Musique. Architecture, Casterman, Tournai, 1976, p.134)
He uses the graphic structure of glissandi textures from Metastasis:
"My own musical research on sounds with continuous variation in relation to time […] led me to lean towards geometric structures based on straight lines: ruled surfaces." (Musique. Architecture, op.cit.)
For the first time, Xenakis had a conflict with Le Corbusier, who refused to grant him the authorship of the Pavilion that he had entirely conceived. Finally, le Corbusier accepted to allow Xenakis to co-sign the work.
Xenakis also realized Concret PH, a short work of musique concrète that was played between the performances of Varèse’s Poème électronique.
Xenakis receives a grant from the European Cultural Foundation, whose jury was presided by Nicolas Nabokov.
March 8: Pithoprakta is premièred at the Festival Musica Viva in Munich by the Bavarian Radio Orchestra, conducted by Hermann Scherchen.
July 20: Achorripsis is premièred in Buenos Aires by the Teatro Colon Orchestra, conducted by Hermann Scherchen.
In the Gravesaner Blätter, n° 11-12, Xenakis publishes his article "A la recherche d’une musique stochastique". This text is later printed in his book, Musiques Formelles (op.cit., p.37). Here he explains the principles of stochastic composition used in Achorripsis, an analyzes an excerpt of this piece.
"There is an advantage in defining chance as an aesthetic law, as a normal philosophy. Chance is the limit of the notion of evolving symmetry. Symmetry tends to asymmetry, which in this sense is equivalent to the negation of traditionally inherited behavioral frameworks. […] Everything happens as if there were one-to-one oscillations between symmetry, order, rationality, and asymmetry, disorder, irrationality in the reactions between the epochs of civilizations." (Formalized Music, p.25)
At the GRM (Groupe de recherches musicales), he meets François-Bernard Mâche, who will be one of his most faithful friends.
October 5: Diamorphoses , a tape work realized in the GRM studio, is premièred in Brussells.
The French première of Achorripsis at the Salle Pleyel in Paris, conducted by Hermann Scherchen leading the Concerts Lamoureux. The serialists and most of the critics assail the work with hostilities.
Summer: première of Analogiques A & B by Hermann Scherchen at his Festival in Gravesano.
September 1: Xenakis, along with two of his colleagues, is dismissed by Le Corbusier.
Stockholm premières of Metastasis and Pithoprakta.
French première of Pithoprakta by Hermann Scherchen.
Xenakis is a member of the jury for the Paris Museum of Modern Art’s Biennale.
Xenakis founds, with Michel Philippot, Abraham Moles and Alain de Chambure the MYAM, an informal research group concentrating on mathematics and music.
May: Enrico Fulchignoni’s short-film, Orient-Occident, commissioned by UNESCO, is presented at the Cannes film festival, for which Xenakis wrote the accompanying electroacoustic music of the same name. He evokes this film with François Delalande (cf. Bibliography, then Interviews).
Xenakis also composes Vasarely, an instrumental work (later removed from his catalogue) for a short-film on the painter by P. Kassovitz and E. Szabo.
He begins to publish installments of his long text entitled "Elements de musique stochastique" in the Gravesaner Blätter, overflowing to issues in 1961. This will later constitute the basis for the second chapter, "Musique stochastique markovienne" of his book Musiques Formelles (chapters II & III in Formalized Music, "Markovian Stochastic Music - Theory and Applications". Here, he introduces a granular representation of sound and integrates a "memory" function to stochastic processes by using Markovian chains.
April 17-23: Xenakis participates in the "East-West Music Encounter" in Tokyo. Other western composers present include: Berio, Carter, Cowell, Sessions, as well as the musicologist Stuckenschmidt.
April 29: presents a concert of experimental music in Tokyo, including no less than eighteen instrumental and electracoustic works by western composers.
Meets Yuji Takahashi in Japan, who will remain one of his most devoted performers. The composer Toru Takemitsu introduces Xenakis to Seiji Ozawa.
Xenakis composes Forme rouge (later removed from his catalogue) for an animated short-film by P. Kalmer.
Summer: Scherchen asks Xenakis to draw up plans for an experimental auditorium in Gravesano.