The Le UN experimental electroacoustic ensemble was formed in 2012 by French free improvising double bass player David Chiesa, and since 2019, it has focused on free or non-idiomatic improvisation. The UN declares itself to be a non-hierarchical improvisational society. The ensemble works according to a few key principles: no recourse to any sort of score or direction, and improvisation is considered not as a style or genre but rather as an attitude to music-making. Improvisation also poses questions about the ephemeral and impermanence: the music leaves traces, but not proof. This experience of immediacy frees the ensemble from the need to be necessary.
The UN ensemble consists of twenty-five members, including a light artist and a performer. It plays in different venues or theatres,
