Ivo Perelman’s name is the first on each disc but the other musicians in his two quartets and duet stand alongside to suggest equal billing. This raises an interesting question over leadership, given the fact that all of the music is, in each case, jointly credited. It might be more appropriate to say that the Brazilian saxophonist is a captain among captains. On first hearing, his horn appears as a dominant colour on the sound canvas, which is not surprising given the metamorphic phrasing and tonal shifts that take him from the weighty-bulky to the flighty-airy without respite. Yet the group sessions are engaging because all of the players have an equally supple feel for time and pitch, which produces arrangements that expand to baroque flourish and contract to a one chord thrash without overly telegraphic signs. This harnessed restlessness can be traced back to the stark, offcentre marches of Ayler, Watts and Logan but a sumptuous orchestral surge comes from the dense outpourings of Matthew Shipp’s piano. When the drums and bass are taken out of the equation for the duet with Shipp, there is a more monochrome character to the music, but its muscularity, certainly with the heft of the keyboardist’s attack, is not diminished. The 13 pieces are mostly miniatures that succeed for their sense of confrontation and playfulness, with Shipp’s ostinatos acting as a carousel on to which Perelman’s skipping, vaulting tones hitch with dark, mischievous sensuality. Both the duet and quartets can stake a valid claim to being at the cutting edge of contemporary small group improvisation where the conceptual reflexes of the players are in line with the advanced nature of their technique.