The deafening shriek that goes up as Fall Out Boy take the stage gives the game away: they are, basically, a boy-band with bigger guns. Their audience, which contains a substantial quantity of kohl-eyed teens, would no doubt disagree violently, craving what passes for punk-rock credibility these days to distinguish them from the uncool kids. The band, you suspect, shrewd players from the land where all success is, by definition, good, would not be so troubled by the comparison.

For the uninitiated, Fall Out Boy are emo. That used to mean tuneful American rock with roots in hardcore and a vaguely alternative bent - now, it simply means multi-million selling American pop music with guitars. It is an overheated, gossipy scene that caters supremely to the excitable, mildly misunderstood adolescent.

Fall Out Boy, however, are genuinely weird, albeit probably not in the way they would like to be. Centre-stage is the ingloriously named singer Patrick Stump. His three bandmates are skinny, photogenic and tattooed. Stump is pale, pudgy and balding; he musters barely a flicker of charisma. To compensate, pouting bass player Pete Wentz and hairy guitarist Joe Trohman leap and twirl behind him like hyperactive children.

They should pay more attention to their instruments: the sound is awful, the expensively precision-tooled record rendered as sludge. Still, the kids are having a riot. In between songs, a girl in a plastic tiara throws up.