Saxophonist Evan Parker’s week of live shows celebrating his 70th birthday began as a summit of all-improv giants. Parker played with Australian trio the Necks, maestros of the art who share his commitment to a many-layered polyphonic improv. It was a fascinating, delicately nuanced and heartwarming display of give and take. Parker often allowed his long soliloquies to be buffeted and spun by the Necks’ famous ebbs and surges of collective sound, but he sometimes intervened, drawing the music out of trance states into more restless episodes.

Where the Necks choose to begin has a pervasive impact on the run of play – it might be a rocket launch of percussion noise from Tony Buck, a double-bass murmur that slowly becomes a hook, or a looping piano figure from Chris Abrahams. The bass method opened this show, with Lloyd Swanton’s quiet proddings initially inviting something close to conventionally lyrical melody from Parker’s soprano sax. Richly woven sax patterns unfolded over Abrahams’s percussive piano, and when the pianist switched to brighter, pearly trills, Parker emitted fraught, exclamatory yelps. The sax fell quiet, flappy, bird’s-wings percussion ushered in a new mood and Parker returned, swapping jazzlike phrases with Abrahams. After an episode highlighting the saxophonist’s low-register expressiveness, a repeating and receding piano figure began a quietly throbbing descent into silence.

The second half began almost classically, with a solo-piano rhapsody that Parker joined with short, seesawing motifs. The set grew darker through deep, thudding basslines and then heavier as bagpipe-like saxophone twisted over a tramping, rock-tinged pulse. Improvisers distrust playing together regularly in case habits set in, but this meeting of minds and methods could bear repeating.

• On alternating nights at Cafe Oto and Vortex Jazz Club, London, until 26 October. Details: Evan@70.