Concret PH (1958)
Brussels World Fair, 1958 : The industrialist Philips commissioned Le Corbusier's famous "Philips Pavilion": "I'll create an electronic poem for you, he said. Everything will happen inside: sound, light, colour and rhythm." Iannis Xenakis designed the architectural blueprint and composed "Concret PH", meant to psychologically prepare the public to the show created inside, accompanied by a musical piece by Varese. 
The 400 speakers that lined the inner shell were meant to fill the space through the sound sparkles of "Concret PH" and achieve a joint emanation of architecture and music, conceived as a whole: the roughness of the concrete and its internal friction coefficient found an echo in the timbre of the sparkles. Orient-Occident (1960) 
The work was originally composed for a film by Enrico Fulchignoni for UNESCO. The film describes a visit to the museum suggesting to compare artefacts produced by various cultures and highlighting their interaction that dates back to the most ancient times. 
From an abstract point of view, the composer regards this work as a solution to the problem of finding highly diversified means of transition, meant to link a type of material to another. One indeed witnesses a varied gradation of mutations, interplays, overlaps, cross-fading, sudden shifts and hidden junction points. Diamorphoses (1957-58)
Continuity and discontinuity within evolution, here are two aspects of the being, whether in opposition or in communion. In "Diamorphoses" this antithesis was worked on in the sections of some sounds strongly opposed to others, and particularly in organisations of continuous variations of average or "statistical" heights. Bohor (1962)
Bohor (referring to Bors the Younger, Lancelot's cousin), is a character from the medieval cycle of King Arthur and the Knights of the Round Table. "Bohor" is dedicated to Pierre Schaeffer. The author deliberately abstained from giving and descriptive information on his piece, letting the listener choose an imaginary route for himself. For this release, we have chosen the 1968 version, revised by Iannis Xenakis himself and as yet not made available to the public. ------------ Even though Iannis Xenakis never made "musique concrète" in the sense given by Pierre Schaeffer, the GRM was a locus for experimenting with his ideas about sound and sound structures. The works, composed between 1958 and 1962, show a boldness as advanced as in his orchestral approach. 
The relationship between Xenakis and Schaeffer was often tense. It nevertheless entailed mutual recognition and respect towards each other's musical approach. Moreover, "Bohor" is dedicated to Schaeffer, as evidenced by the letter Xenakis sent him on October 8th, 1968: "Dear Pierre, I have decided to dedicate Bohor to you, out of friendship and gratitude for your contribution to music. I hope you are pleased with this." Schaeffer found the piece disproportionate in terms of intensity but was indeed pleased by the dedication.The four pieces presented here, all produced at the GRM, undoubtedly demonstrate the experimental intent and the strictly "physical" character of Xenakis' music, in that it provides the audience with a listening experience of a rare intensity. (François Bonnet & Christian Zanési)