The Dutch company Philips wanted to participate in the 1958 World’s Fair in Brussels – the first after World War II – with its own temporary pavilion. It invited Le Corbusier, knowing his international reputation. Upon approaching Le Corbusier, the firm’s artistic director, Louis Kalff, realized that the architect was more interested in the audiovisual show inside the pavilion (a distant dream of the painter-architect that had never been fulfilled) than in its architectural coverage. After rejecting Gehry Reitvield’s proposal for the architecture of the pavilion – the architect of the neighboring Dutch pavilion – Le Corbusier drew a “stomach-shaped” sketch and entrusted its elaboration to Xenakis. Anxious to leave the interior space completely unobstructed and to offer optimal acoustics, the architect-composer turned to left-handed surfaces and covered the plane of the “stomach” with thin reinforced concrete shells in the form of hyperbolic paraboloids and conoids. The descriptive geometry plans that emerged from this Xenakis research will be used when the firm seeks to consult with engineers specializing in self-supporting structures. The Belgian company Strabed, chosen for the construction of the pavilion, succeeded in respecting Xenakis’ plans and built one of the leading icons of twentieth-century avant-garde architecture. In addition, two “mathematical objects” (one suspended inside and a second placed at the entrance) were designed by Xenakis.
Finally, Le Corbusier, enjoying total freedom, imposed the participation of Edgar Varèse for the composition of the music of the show and solicited Xenakis to compose two minutes of an interlude (Interlude Sonore, 1958), which would later be re-recorded under the title of Concret P.H.
The Philips Pavilion was a huge success during the Exposition. However, the dispute between Le Corbusier and Xenakis about the authorship of the pavilion’s form became crucial and deteriorated their collaboration. A year later, Xenakis left the studio at the initiative of his boss.