1) AMM is a British free improvisation group, founded in London, England in 1965. 2) Japanese arranger. Circle: ShibayanRecords. 1. AMM have never been well-known to the general public, but have been, in their own way, hugely influential on several generations of adventurous musicians. AMM has been called "legendary" and "groundbreaking." They are notable as the perhaps the first musical group to deliberately try to make music not related to any established musical genre: as Michael Nyman wrote