The surroundings are a little more elegant, but the new Thursday night sessions at north London's Progress Bar convey much of the old Vortex Club's tantalising sense that you're a witness to something that is only going to happen this way once. This week's guest was world-class guitarist Phil Robson, who co-led an exciting quartet with former Loose Tubes trumpeter Chris Batchelor.

Robson's most high-profile recent incarnation has been in the trio he has run with Americans James Genus and Billy Hart, but this band was a more fusion-oriented affair, with Batchelor deploying a variety of trumpet bugs (electronic pickups) and Robson sounding raw and metallic. They made no secret of the fact that some of the material was in road-test stage, with drummer Gene Calderazzo and electric bassist Phil Donkin wrestling at times with the rhythmic disruptions of the themes. Batchelor, a fine trumpeter who intriguingly blends Miles Davis's shrewd pacing and evocative long-note sounds with something of Harry Becket's bubbly phrasing, was similarly straddled between the appeal of hardware that expanded the horn's possibilities (to make him sound dramatic and ambiguous) and reduced it (to occasionally resemble an electronic penny-whistle).

Miles' music of the Bitches Brew era coloured the opening episodes, before a punchy, cop-show theme unfolded over Calderazzo's fierce drumming. Chris Batchelor played taut rhythmic figures over this passage and busier, buoyant ones over the driving rimshot pulse that followed it. A fast, bluesy account of Joe Lovano's Fort Worth brought a freewheeling Robson break. A Thelonious Monk exploration was slightly distracted by the tonal peculiarities of the trumpet effects, but a rhythmically adventurous Milesian fusion feel soon returned. Exploratory jazz with enough bite, conviction and invention to suggest a combination worth pursuing.