Not quite an ‘offshoot’ of AMM but featuring most of the group’s members at the time, Silver Pyramid is an eighty-minute performance from the Music Now festival, based on an Eddie Prevost score that took the shape of the titular object and an accompanying, abstruse text. The details of who exactly played what are lost to time, though you can definitely hear the likes of Prevost, Keith Rowe, and Cornelius Cardew here. What’s most impressive is how startlingly contemporary this sounds, a gorgeous, low-level scrum of clatter and hum that you could easily mistake for an electro-acoustic improv set from the past ten years. It breathes more slowly than contemporaneous AMM recordings, and glows with warm embers of noise.

– Jon Dale