Another fine evening at AMR in the company of a group of inspired and inspiring musicians. The story goes that the long-established Chicago Underground duo of cornettist Rob Mazurek and percussionist Chad Taylor invited two mainstays of the London improv scene, pianist Alexander Hawkins and bassist John Edwards, to join them in forming a new quartet called, deep breath, Chicago/London Underground. Personally I would have called the group Them after the initial letters of the four members’ surnames, but I guess Van Morrison got there first. Meth would have been a possible, if fairly unappetising, alternative. But I digress.

This was, I think, my first live acquaintance with any of these musicians, although both Hawkins and Edwards have been on my radar for some time on account of their regular appearances on my Evan Parker gigs page. With the frequency of their collaborations with Parker testifying to their ability as improvisors, it comes as no surprise that the saxophonist joined the full group onstage at a recent concert in Slovenia, only a week or so before their appearance in Geneva.

This being, as noted above, a fairly new collaboration, there was a freshness and a vitality to the performance that repeatedly cut through the received language of improv. With his permanent scowl and unnecessary sunglasses, Mazurek cut an incongruous onstage figure. I could have done without his occasional vocal interjections and his use of cowbells as a percussion instrument, which was presumably intended as some kind of humorous reference to the fact that we were in Switzerland. But once he got down to business on cornet the results were miraculous, as his moody, hyperactive lines fell into sublime interplay with Hawkins’ sparkling piano and the gut-churning twists and turns of Edwards and Taylor’s rhythmic structures.

Throughout the evening’s two sets, duo and trio sections alternated with full-on ensemble material. In the first half, a long, sensitive duet between Hawkins and Mazurek saw the smoky haze of the Chicagoan’s cornet sustained by Hawkins’ richly expressive language on the piano. Taylor for his part, when he wasn’t etching the radiant tones of the mbira into the group’s sound, was relentlessly probing and energetic behind the kit, while Edwards propelled the ensemble forward with his dreamlike arco and pizzicato work.

The second set began with a breathtaking dialogue between Hawkins and Taylor. Drawing on vast reserves of energy and dexterity, the pianist sculpted waves of tense, knotty melodies that worked their way insidiously into the wide-open expanses generated by Taylor. The drummer ceded ground to Edwards, who joined Hawkins for an engrossing duo section of their own. With an audacity that was as thrilling as it was unexpected, the four men came together for a blistering quartet section driven by an infectious rhythmic groove, courtesy of a sampler controlled by Mazurek. This extended finale was a perfect example of Chicago/London Underground’s gleefully inclusive approach to improvisation, encompassing freedom, rhythm, dissonance, melody and all points in between.