One of the most versatile contemporary improvisers is without a doubt multi-instrumentalist Joe McPhee. A frequent guest of various and sundry musicians across the globe, he can be thrown into a surprisingly wide range of contexts and yet blend cohesively while retaining his distinct personality.

On this disc, McPhee — on trumpet and saxophone — teamed up with bassist Pascal Niggenkemper and drummer Stale Liavik Solberg for a concert at JACK in Brooklyn in December 2015. The session was recorded by Jonathan Goldberg, mixed by Fred Lonberg-Holm, mastered by John Butcher and released on Clean Feed, the Portuguese label that is documenting a lot of the exciting improvised music being played these days.

Imaginary Numbers is a three-track offering that is dedicated to John Coltrane and includes, as a center piece, a creative take on A Love Supreme that echoes some rhythmic figures from Coltrane's original composition, but is a wholly fresh piece of music. Nothing like a deconstruction, it is more a nod in Coltrane's direction and a meeting of kindred spirits. The music and the timbral and tonal colors echo some of the original, but the music is entirely the band's own, moving from subtle lyrical phrasing to powerful extended techniques (like the saxophonist's howling into the horn and the altissimo bowing of double bass). This is not a cloning of the ideas of Coltrane's great quartet, but an extension of the spirit of Coltrane's genius, which was, as we know one of inspired instant composition.

The opening piece, simply called "i" is probably the most engaging, featuring for a good part of the time generous swirls of McPhee's dynamic trumpet and the inspired concoctions of bass and drums, with sympathetically inventive verve. Trumpet gives way to sax about halfway through, and at a little over 23 minutes, this is a suite-like piece, a mini-symphony of sorts, wherein the creative energies of the players are given free rein.

The set closes with a nine-minute piece called "Zero" that starts strong and hot, but gets more minimalistic, dying down to quiet babbling of drums, then bass, with lots of space and careful listening. McPhee's trumpet comes in again as the band builds to a climax then returns to an exploration of textures and sonorities primarily via arco bass, eventually engaging the full forces of this inventive trio with a return of drums and McPhee's keening tenor sound.