The fortunes of former child stars are famously mixed. Some slide into ignominy and miserable early death. Others are spurred by their early fame into even greater success. Most simply vanish from public view, remembered only by a handful of die-hard fans, which appeared to be the fate of Hanson, three prepubescent, devout Christian brothers from Tulsa, Oklahoma, who sold 8m albums in 1997 on the back of Mmmbop, an irrepressibly perky song that quickly became Mmmbearable.
Their success was fleeting, but this seems only to have strengthened the trio's resolve to claw back their fame. Their website strikes a tone of steely determination. We are informed that their hit album The Middle of Nowhere "opened up a crucial demographic of fans".
The crucial demographic of fans may have shrunk since - tonight's acoustic show is hardly packed - but you can't deny its diversity: a mix of scowling teenage moshers, suburban-looking late-20s couples and hysterical weenyboppers, some of whom are so weeny they have arrived with their parents in tow. Everyone appears to have a word-perfect knowledge of every song, suggesting that some pop fans at least are less fickle in their affections than is widely supposed.
Hanson's gimmick was that, despite their tender years, they played instruments and wrote songs. The sound they make isn't unpleasant, but nor would you go out of your way to hear it - a blend of close-harmony vocals and default-setting boyband lyrics. It is like Crosby Stills and Nash sponsored by Clearasil, an impression underlined by a cover of Teach Your Children.
The overall impression is of a band trapped in a no-man's land between teen-pop and serious musicianship. The crucial demographic of fans loves them, but not in the way you suspect Hanson want to be loved. Introducing a cover of Ain't No Sunshine, Isaac Hanson notes that "Bill Withers did a great version of this song on a TV show called the Old Grey Whistle Test, which you might have heard of." No such luck: a puzzled silence falls over the crowd. Then he starts singing, and they start screaming again.
