David Holmes & The Free Association, Jazz Café, London

There's no stopping David Holmes. Not content with his soundtrack work, remixing, pick'n'mix rock-and-soul collections and albums released under the name of his band project, The Free Association - introduced on 2001's Come Get It I Got It album and let loose on last year's excellent David Holmes Presents the Free Association - he's got the live bug bad. How many times have The Free Association played in the past few months? Tough to keep count, but with shows at the 100 Club, 93 Feet East, Shepherd's Bush Empire and the Royal Festival Hall, in London, and at Glastonbury, they've had plenty to be getting on with.

Clearly, Holmes is trying to turn The Free Association into a flesh-and-blood live unit rather than a DJ's because-I-can doodle. They limber up nicely at first, too, largely because of the interplay between the two vocalists, the irascible Californian MC Sean Reveron and the coolly crooning Petra Jean Phillipson. Sporting a Motörhead T-shirt, the dread-locked Reveron is a cracking front man, rapping with urgency and not letting an inch of the stage go to waste. He becomes so excited that he unwittingly treads on something important, cutting the bass out and stalling the show. As the lank-haired bassist ticks him off, Reveron retorts with a comical: "Well, I didn't know, did I?"; 10 minutes later, he's back on stage, grinning sheepishly and offering, "I only wanted you to enjoy yourself," in his defence.

Musically, the standard band of bass, drums and guitar cook up a raucous rumpus of swamp blues, jazz and funk, hauled up to date by Reveron's rapping and sent in the direction of the dancefloor by Holmes's side-stage sampling and scratching. But much of the stealth and subtlety on the Presents the Free Association album is lost, replaced by beats and grooves designed to get the crowd to "free that English ass", as Reveron puts it. It works, up to a point, but it is a little repetitive, with limitations that become obvious as any outbreaks of audience ass-wobbling slowly wilt.

Not that there aren't some great moments. "Everybody Knows" thunders along nicely with a low-slung, Batman-theme-tune vibe. And on the Phillipson-sung forthcoming single "Sugarman", a cover of a song by the Sixties singer-songwriter Sixto Rodriguez, the pace shifts to something soulful; it sounds not unlike a cross between Beth Gibbons's widescreen work with Portishead and her more rustic Out of Season album. When the song is wheeled out a second time for the encore, though, the worry sticks. Holmes has a lot on his plate. But he needs to flesh out The Free Association a little if he wants them to become much more than a moderately entertaining diversion.