Pop Music: Michael Franti and Spearhead

Children reared on the story of David and Goliath must scramble for their slingshots whenever Michael Franti walks down the street - the man is enormous. He's a big cheese in the rap world, too, almost a Cheddar I'd say, but he still lets the other members of his new band Spearhead take the stage first for a song on their own. They're a well-matched bunch of musical eccentrics, kitted out in stripy stocking-hats, sprigs of dreadlocks and outfits that make George Clinton look like a City stiff.

When Franti rises to the mike, you know you're in the hands of a master. In the hard-hitting rap duo Disposable Heroes of Hiphoprisy, he proved his verbal dexterity by wrapping his tongue around some bulky rhetoric on songs like "Television (Drug of the Nation)". Although Spearhead mine a much baggier groove, he can still rap faster than Judge Ito can dismiss jurors. I bet he could even do that "Red Lorry, Yellow Lorry" thing if you asked him. It's fun, too, to hear him push rap's magpie sensibility to its limits - he slips in and out of lyrical steals from the Specials and the Monkees just as the band get on with pickpocketing that sleepy "Walk on the Wild Side" bass-line, and you can barely hear the joins.

There's a warm rapport among the band members which suits the more expansive "Dream Team", but can also give way to steely discipline on the hard funk of "Hole in the Bucket". But tonight is, more or less, party night. Franti has loosened up since Disposable Heroes - television is still the drug of the nation, I'm sure, but the adverts are better these days.

You can still glimpse his old severity - on "Of Course You Can", he looks disgusted at our lame contribution to the call-and-response section and tells us so. But it's eclipsed by that part of him that belongs on rowdy stag nights. Tonight, we get a flash of his butt. This would not normally be worthy of note, if it didn't mark an odd sort of metamorphosis - imagine Dame Kiri Te Kanawa doing likewise and you'll understand. Afterwards, he's very pleased with himself. It must be satisfying rapping about racism and homelessness, but there's clearly nothing to beat a good moon.