There is something oxymoronic about the "jazz-rock" label. If such a fusion exists, it's surely jazz that provides the oxygenation part and rock the moronic. As with oil and water, chalk and cheese and concepts such as "military intelligence", some components don't quite hang together. Led Bib, a Mercury-nominated quintet led by drummer Mark Holub, are the latest London group to find this.

Fronted by two alto saxophonists, Paul Grogan and Mike Williams, they have less rock and more jazz in their makeup than Polar Bear or Acoustic Ladyland. They gave the cauldron an energetic stir last night, creating much bubbling, spitting and fizzing, some of it spectacular, yet their volatile brew never settled into valid music with a character of its own.

The best aspect was Holub's writing. Aural Assault, Stinging Nettle and Manifesto for the Future were snappy, bop-informed lines charmonised by sax over edgy drum and bass beats. But as soon as the solos began the rhythm section, including Toby McLaren's distorted Fender-Rhodes keyboard, erupted into full volume, thudding crass four-tothebar beats over which meaningful ideas became impossible.

Williams, aware of the "outside" harmonies of Steve Coleman and Greg Osby, survived this boring onslaught better than Grogan, a schooled soloist whose fluency would be better served in a less fashionable band. Tough decision.