"Relevant" and "contemporary" aren't words that spring to mind in regard to flaxen-haired boy band Hanson. But the trio might be forgiven for thinking otherwise. Though their biggest hit, Mmmbop, was back in 1997 and it's been four years since they released an album, the fans are still screaming.

Having survived the indignities of child stardom - the hits dried up as the hormones kicked in - Hanson appear on the brink of a comeback. Namechecked by credible peers including Avril Lavigne and Michelle Branch, they've released an internet-only EP and recorded their third album, Underneath, on their own label. A mix of chunky pop melodies, close harmonies and early-20s angst, it is the sound - and attitude - of a band making up for lost time.

But this lunge at maturity has its drawbacks. Forgetfulness, for a start. "It's been four years since we played here," says Taylor. Actually, it's just over a year and, once again, they've brought their acoustic show with them. For a pop band, they're not much fun. Watching the still boyish figures of Isaac, now 23, Taylor, 21, and 19-year-old Zac stuck to their stools and wearing stern expressions sits uncomfortably with the exuberance of their songs. Even Mmmbop feels more like a wake than a celebration.

Their solo spots only make things worse. Isaac, now a proficient guitarist with an impressive growl, rocks admirably - more old bluesman than teen idol - but heart-throb Taylor's Crazy Beautiful is slow and painful. He jumps up during the lively This Time Around looks awkward. Zac, for whom the fine line between irrepressible and irritating was once a blur, just hides behind his drums. Even the Crocodile Rock-styled Rock'n'Roll Razorblade can't escape the fact that Hanson make growing up look like hard work.