The art of collective improvisation is often overlooked by jazz groups still in thrall to the bebop ideal of theme-solos-theme. British saxophonist Stan Sulzmann is ideally qualified to breathe new life into the tradition: having spent years as a sideman to the likes of Michael Brecker and Gil Evans, he is an instinctively ego-less player.

Sulzmann is currently promoting his Jigsaw album, a project that teams him with the Marc Copeland trio. They are a New York combo whose members - pianist Copeland, drummer Jochen Rueckert and bassist Drew Gress - clearly share his collectivist ideals. Indeed, for much of the performance it was hard to know where to turn your ears as the four instruments glided in and around each other, weaving a tapestry of profound complexity.

The Wayne Shorterish Evie began the set, with Sulzmann doodling exquisitely in the margins while Copeland's glimmering piano turned harmonic structures to soft putty. As the piece unfolded, the impression was of taking a rambling bus journey, where the scenery and weather constantly change without ever drawing attention to themselves.

A Copeland composition called Dark Territory deepened the mood, exploring the kind of melancholy terrain beloved of such British jazz composers as Michael Garrick. Rueckert's cymbal brushwork sounded like rain on a roof, while Copeland's piano lines grew ever more mercurial as he seemed to struggle to express something beyond mere notes.

Some injudicious planning found the second half rather too dominated by very slow pieces. Still, A Warm Rocky Place was appealingly languorous with its swirls of daydream melody. By now many sections of the audience looked slightly glazed, so the band slipped into overdrive for the finale. No Discussion was a tricky extemporisation of one short rhythmic phrase. It found Copeland counting frantically out loud and Rueckert shouting in triumph as he negotiated the increasingly amorphous bar-lines. A surprisingly gung-ho way to end a deeply introspective evening.