For this study, the author, still little familiarized with the experimental music, chose a little diversified musical matter. He thus limited the number of sound bodies and, by seeking the originality of the musical objects as of the sound recording, he reduced handling electroacoustics to the minimum.

The “accidents”, unexpected sound elements burst in are produced here by rhythmic agitations of rods intervening in the body of a note of piano (prepared piano). The accidents being taken for themselves the effect of surprise accompanying them finds some attenuated and there remains an internal logic of the sound event.

(Excerpt of the program of the 1st concert of the Festival de la Recherche 1960)