Released on a mini-album Invisible is a short (19’35”) 6 part suite for soprano and 2-track tape sung by Irene Jarsky on texts by Tchouang-Tseu by Jean-Claude Risset, who alongside the likes of Pierre Henry, Pierre Schaeffer and Pierre Boulez,  brought early electronic music into new, unexplored territories. With a training in physics, piano and composition, he is often seen as the first French musician to ever use computers for composition and music production.