More than half a century has elapsed since the founding of the legendary British free improvisation group AMM. Improvisation has gone a long way in the meantime; it has seen copious conceptual subdivisions and found its place on all musical fronts. The mystery surrounding AMM has not faded; to the contrary, even nowadays it carries a particular appeal due to its engaged, intelligible and nonetheless radical message, opening the door to all untrained musicians and listeners directly into the heart of sonic experimentation. Eddie Prévost, John Tilbury and Keith Rowe are all outstanding figures in contemporary music history – Prévost as an ingenious percussionist and theorist, Tilbury as one of the most distinctive performers of post-Cageian piano composition, and Rowe as a perennial star of minimalist ‘tabletop’ guitar improvisation from the circles of Erstwhile Records. In short: to trace the history of improvisation without AMM would be an impossible task.