The free improvisation group AMM have, remarkably, been active since 1965, and founder-member Eddie Prévost has been a constant presence. Cornelius Cardew was a long-standing member, and occasional collaborators include Christian Wolff and Evan Parker. Ornette Coleman was apparently asked to leave.
The group may be exactly twice my age, but, as one would hope from free improvisers, they still perform with freshness and huge imagination. Their performance in the fashionable Café Oto in Dalston, London was a testament to the sustainability of improvisation as a musical way of life.