Over the last couple of decades, Fred Frith has honed his extremely inventive solo electric guitar sets, for which he often lays the guitar flat on his lap and stimulates it with various objects including paint brushes and ball bearings, summoning strange and unexpected sonorities. Here, leading his long-standing Bay Area trio, he demonstrates a similar degree of lateral thinking and restless creativity, put to use navigating wide-ranging free-rock that’s positively bursting with ideas. The first disc is an uninterrupted, hour-long live performance by the trio, which wanders unhurriedly from lumbering riffage to diaphanous soundscape and mellow rim-shot groove via loping desert blues.

Along the way, Frith works up a dizzying array of effects, from backward swirls and strangulated feedback, to a strange bagpipe bleat and the sound of an angry mosquito trapped under a glass. The second disc finds the trio augmented on two tracks by Danish saxophonist Lotte Anker – who slides from an assured, earthy tone to keening cry – and on two more pieces by Portuguese trumpeter Susana Santos Silva – who unlocks a trove of extended techniques, from liquid ululations to blustery barrages. It’s rare indeed that improvised music is simultaneously as accessible and cerebral as this.