While the true nature of an improvisatory encounter takes time to reveal itself, sometimes the beginning is a harbinger. Take, for example, the opening from another session in which saxophonist Evan Parker participated nearly 60 years ago, Peter Brötzmann's Machine Gun: the evocative strafing from the assembled horns over a martial beat is preparation for all that follows.

Something similarly prophetic yet very different aesthetically happens with the first 90 seconds of May Spring Last a Lifetime, Parker with younger compatriot Tom Challenger, both playing tenor saxophone. The 53-minute improvisation starts with only the slightest breath from one amid a chittering nest of key-clacking from the other, quiet and investigative rather than bombastic and confrontational. The former adjectives remain the modus operandi for much of the piece, details of which are beautifully present in this recording from Ramsgate's Arco Barco studio.

Though there are moments of abstraction, Challenger and Parker err on the side of tonal purity, almost choral-like, reserved and focused and often dropping into hushed, sparse segments that draw you closer to the speakers for fear of missing a subatomic detail.

The sound of keys opening and closing becomes a motif to which the pair returns a few more times, functioning to a point as resets. Between those guideposts are a baton relay of offset lines, calls during a foxhunt across woodlands, solemn buzzing and, during the last third of the duration, circular breathing as a means for consonance and counteraction.

When so many forays of this kind come across as the tying together of as many threads as possible into a tight mass of sound, Challenger and Parker instead spend their time unraveling knots, with patience and foresight into how pulling too hard or too haphazardly will just create new tangles. After a restrained circular breathed duet in complementary registers brings the piece to a close, there is a laugh and Challenger saying, “That was a bit of journey.” Indeed.