De part et d’autre (1995) is a short piece of an essentially rhythmic and repetitive nature. The instrumentation is not determined, which leaves a large part to the creativity of the performers without going as far as improvisation. Indeed, it is the musicians who decide on the sound and instrumental effects used during the piece, as well as the clef (G, F or C) in which they read the score. Harmonically speaking, all the sounds heard belong to the acoustic scale (C, D, E, F sharp, G, A, B flat). Thousands of radically different versions can thus be obtained, even with an identical instrumental formation.

The Soledad ensemble has produced a superb CD version (Virgin Classics label 7243 5 45503 2 4).

The world premiere of a version for instrumental ensemble under the direction of the composer took place on November 5, 1995 in Brussels.