Group improvisation can be magical when all the stars align and the right people are matched. Add a live audience, and the whole thing may well rise into music of inspired and inspirational magnitude. To say that all this applies to this disc is not overstatement but a pretty down-to-earth description. Joe McPhee's keening tenor and Jeb Bishop's fat trombone tone are the melodic twins that spin and intertwine in enlightening ways, while bassist Ingebright Haker Flaten and drummer Michael Zerang stir the cauldron of ideas that steam up the quartet to telepathic compositional frenzy.

Five pieces are the result � three meaty, eloquent and full-developed movements, book-ended by a six-minute overture and an eight-minute coda. The cohesive thematic development and generally unified thinking that run through the whole session, a live date at Oslo's Victoria Theatre in February, 2009, make this a five-movement work of improvisational brilliance. Chicago-based improvisers Bishop and Zerang join New Yorker McPhee and Sweden's Haker Flaten in a complicity that couldn't be more intimate and well-meshed.

Right from the opening duo statement of sax and trombone that drifts, two-minutes in, toward a free-form rhythm section ramble with trombone solo, into which the sax leaps like a rampaging tiger, one senses that these guys can let loose as well as turn musical ideas as craftily and surprisingly as the most deft magicians. They also seem to speak complex musical ideas as if they were created by one mind.

Along with the kaleidoscopic yet concordant musical ideas are the dramatic shifts in mood, from peaceful harmonious unity, to melancholic introspection, to fiery, no-holds-barred pouncing, sometimes all within a few minutes. The five pieces, as short as 6:48 and as long as 14:54, all work as self-contained movements, but the energy and vibe flow one into the other in an organic manner.

The sonic pallet is another remarkable feature, as each player is able to coax the comfortingly familiar beauty of their instruments' timbral qualities, but can equally surprise the listener with Promethean articulations (aided by the use of mutes in the case of Bishop's trombone). Part and parcel of these articulations is the unabashed and refreshing exploration of what used to be known as "extended techniques," but here, as in the best releases of contemporary creative improvisers, have become part of a poetically reinvented language that yields powerful results.