"Most of the time I don't know what I'm doing," the guitarist John Scofield confided to a Jazz Cafe audience greeting him like a long-lost relative. Like a lot of throwaway lines, it had a sliver of conviction in it. Though the convenient jazz cliche is that it is all dreamed up on the fly, Scofield often genuinely seems on the edge of what he knows.

In London for the first of only two gigs in the UK this summer to support his excellent crossover album Bump, he was accompanied by an oddly balanced trio with a second guitar plus bass and drums. But a maelstrom of dense funk percussion, the shrewd use of samples and a vigorous two-guitar dialogue caught much of the mood of the disc, and intensified the after-hours atmosphere as the show went on.

The rhythm section, straddling the drum-machine feel of hip-hop and drum'n'bass and the more open and flexible vibe of jazz, did pretty well at leaving the inviting spaces Scofield likes, though he had to carry the show more than he does with a looser drummer like Bill Stewart. The slow features chimed and snarled with Scofield's characteristically warped chords and singing treble figures, the heavy-hitting grooves turned clipped, corner-of-the-mouth themes into flowing improvisations, and imaginative use of microchips allowed him to mimic the garrulous, interrogatory energy of vocal raps. Most gifted jazz improvisers sound uncomfortable, lazy or opportunistic in their funk incarnations, but Scofield always sounds as if he's still developing, and having the time of his life doing it.