Impermanence is an improvised encounter between a tightrope walker and an improvising musician. This performance lasts between 20 and 30 minutes and is designed in collaboration with the organizer. Josselin has notably performed with Alexandra Grimal (saxophone), Elise Dabrowski (double bass, vocals), Edward Perraud (percussion), Louis Sclavis (clarinet), Benoit Travers (percussion), and Patrick Charnois (saxophone), among others.