| Dated: | 1962 |
| Instrumentation: | Eight or four-channel tape. |
| Timing: | 21'30 |
| Premiere: | December 15, 1962 at the Salle de l'ancien Conservatoire in Paris. |
| Dedicated to: | Pierre Schaeffer |
| Commissioned by: | |
| Published: | Editions Salabert |
| Created at GRM (Groupe de Recherches Musicales) in Paris. Recording available from Electronic Music Foundation Media EMF102 |