Iskra 1903 were a trio of Derek Bailey (guitar), Paul Rutherford (trombone, piano) and Barry Guy (bassist). It’s a tight line-up, but mighty in its collective energy, and the playing here approaches a kind of platonic ideal for free music – if such a thing could be said to exist, or would even be healthy for free music. The power here is in the mindmeld between participants, with Bailey and Guy repeatedly melting into each other, Guy’s strained arco passages tangling with Rutherford’s disruptive piano, or the latter’s trombone carving multi-angled shapes out of the ascetic air of London’s Institute for Contemporary Arts, where the sessions were recorded.

– Jon Dale