Rock: The cat in the hat comes back

Shifting a free ticket to last Monday's Jamiroquai gig at the Forum in London proved surprisingly difficult. Friend after friend declined with disdain, even a touch of outrage. It was like offering a bootleg video of Crash to Mrs Whitehouse. Much of this has to do with Jay Kay, the Cat (or Prat, according to taste) in the Hat, the frontman much derided for his retro pretensions and Stevie Wonder complex, an irritating skinny white boy frugging and shrugging to sub-Seventies funk.

Yet the latest album, Travelling Without Moving, ambled into the Top 10 without too much effort, the three London gigs (including one at the Royal Albert Hall) are sold out, and there's the ineluctable fact of Jay Kay's pounds 2m sports-car collection. So I was curious to see what sort of youth style is in force at a Jamiroquai gig: probably Afghan coats marinaded in patchouli, long skirts with bells on and road-protester chic (the Merc, Aston and Ferraris notwithstanding, Jay Kay is a fervent advocate for Planet Earth; he's to petrol what River Phoenix was to drugs).

Well, there are very few hats, which comes as a surprise. Instead it's a clubby crowd with clean hair and scrubbed faces; mostly white, but with just enough negritude to confer chic. Jay Kay's headgear doesn't disappoint: a giant, deconstructed top-hat in cerise fake fur, worn with a matching zippered top. From this distance he looks like a collectable plastic figure shaken from a pack of Fruit Loops: his face is invisible unless he tips his head right back. The music is entirely predictable, a pleasant, accomplished groove, bolstered by a horn section, over which Jay Kay - the Mick Hucknall of the underachiever generation - adds a few vocal doodles and a surprisingly warm and friendly stage presence. It's clear you're not dealing with the giant ego and self-regard of a Noel Gallagher or a Polly Harvey here. His antics - bouts of knock-kneed, pigeon-toed dancing, pretending to conduct - are greeted with screams of approval from the crowd. One of the most touching moments comes during the didgeridoo break (I'm afraid so) when, out of the spotlight, he goes into one of his dreamy, solipsistic dances, as unselfconscious as a kid bopping in his mum's front room. It's so artless that you can't help smiling.

Despite this, the one-and-a-half-hour set, slick though it is, remains relentlessly level: never more than competent, and always less than inspired. Still, he gets a stadium-star's response, especially when he teasingly pulls down his zipper a few inches. The only moment of drama comes when he snarls: "I've lost my licence and I'm pissed off." After this week, he should be walking on air.

Soho Live Week has been serving up handy-pak portions of new-ish acts at the London Astoria 2, in conjunction with Radio 1. This means that the evenings are geared around the listeners in radioland rather than the punters. Sets are brisk and abruptly curtailed, and in between you have to listen to interviews with overpriced-creamcake sellers, club owners and other Soho types. It means that you never get to hear too much; but then neither do you hear enough. Chester band Mansun (Tuesday), managed to be both perfunctory and intense in their half-hour, which should ensure them an enduring musical career. On disc, male-slut rock like "Stripper Vicar" is as shiny and crackly as a honeymoon bed-sheet; live, with added pile-drivers and industrial lifting gear, no one would dare smirk at their bouffant Peter Perrett hair-dos. At the end, Eddie Izzard-lookalike Paul Draper tears off his guitar and storms off, which could be an affected strop, or just the satisfaction of a job well done.

Thursday's gig showcased three bands whose unifying quality was, my highly tuned ear concludes, that they were all American. First off were the tuneful Imperial Teen, about whom it suffices to say: blonde chick drummer! She changed places after a few numbers and proved to be as adept on vox as sticks. In fact all of them, two guys, two gals, swapped instruments and vocals like luvvies in a fringe show who juggle, swordfight and play the trumpet just to prove how damn versatile they are. Still, they were the only oestrogen I got all week, so I liked them. 3 Colours Red are nowhere near as sensitive as the film of the same name: three black-clad, splay- legged, tattooed death merchants bludgeoning their way through a set of songs with single-word titles (single-word lyrics, come to that). This is where the mosh-pit really kicks in, and hysterical 15-year-old boys are passed over the head of the crowd to the security team, who catch them nimbly by the bollocks and the collar and restore them to their feet.

Last up are the Presidents of the United States of America, from which we can deduce that the art of band nomenclature has declined stateside since the heady days of the Dead Kennedys. The Presidents comprise a Muppet on drums, a baldie in clown-shoes, and a boy next door in a painter's overall. The music is cartoon-metal-whimsy performed by sunny optimists. Songs like "Dune Buggy", "Volcano" and "Bug City" overlay nosebleed rock with nonsense couplets ("happy campers / poop in their Pampers") and bizarre humour, although it's hard to smile when your head's in a vice. Nice boys, they namecheck London Town in their songs, thank us for coming and even thank Radio 1. They bounce back on for an encore of "Video Kills the Radio Star", pinching their noses for the silly voices - and indeed it is the strangest sight of the week when mosh-pit mania meets the Buggles.

Nicholas Barber returns next week.