These Variations represent an unprecedented form in the repertoire of acousmatic musics: this is a real "theme and variation" in the classic sense of the term. In their variations, (whether named as such or not), composers had tried, up to now, various games on a sound body, the multiplication of spaces, morphologies, timbres, multiple possibilities of software and machines. They had explored their subject in all directions by declining the points of view, the stories, the moods.

Here, everything begins with a 66-second theme consisting of easily memorized sounds, well characterized, so that listening sounds are still detectable, even transformed. Variations Acousmatiques show that it is possible to develop a great freedom of creation in a stylistic framework allowing the listener to refer effortlessly to the initial formula.

The strength of the writing, the coherence of the explorations, a kind of will at once free and insistent organize a game whose original material, always recognizable, lends itself to limited transformations which are only more expressive. Thus, in development, the reference to the above is never lost.

These eleven variations chained with rigor use methods directly borrowed from the instrumental genre: retrograde movement, mirror, modulation, segmentation, increase and decrease, variations on a partial pattern.