Little needs to be said of percussionist Tony Oxley’s credentials as a figurehead of improvised music – either through his pioneering mid-1960s work with Gavin Bryars and Derek Bailey in the Joseph Holbrooke Trio, or later trans-Atlantic liaisons with Cecil Taylor and Anthony Braxton. These previously unheard snippets from his own archive underscore his passionate, unswerving commitment to non-idiomatic sound creation. The first tranche (recorded in 1974 but edited into their final forms between 2005 and 2020) feature what looks like a conventional quintet with drums, bass, trumpet, piano and trombone, but deal in dense abstractions augmented with tactile electronic treatments.

Anyone who has seen Oxley perform live will also recognise the cavernous clangs and scrapes of the enormous cowbells and gongs with which he famously pimped his drum kit. The second session, also from 1974, is an intense 14-minute piece, again for quintet, this time showcasing the shrill shrieks and tart scrabblings of Phil Wachsmann’s violin and Larry Stabbins’ juddering sax honks. A much later session, from 2016, has Oxley concentrating on electronics while Stefan Hoelker adds acoustic percussion, the duo conjuring ghostly emanations and diffuse soundscapes. It’s a pretty convincing survey of a life devoted to serious investigation.