poème > sound spatialization. Varèse, and also Xenakis to some extent, exploits and organizes the sound material of the Poème électronique as “... the basis of an internal structure, expanded and split into different shapes or groups of sound constantly changing in shape, direction, and speed, attracted and repulsed by various forces.” The three tracks of music were delivered to groups of loudspeakers (Lsp. gr.). to be spatialized in the space of the Philips Pavilion. Some sounds were emitted by whole clusters of loudspeakers simultaneously, others were sent to travel along routes of loudspeakers.