Like Sparks and Soft Cell, Erasure perfected the combination of a camp, falsetto vocalist (Andy Bell) and a frowning bloke behind a synthesiser (Vince Clarke). In their commercially unassailable heyday, the pair's ridiculously uplifting pop singles hung around the charts so long they had to be removed by security. Between 1986 and 1994, every bar seemed contractually bound to play Erasure at least four times a night. Meanwhile, Bell entertained the crowds by "flying" on a gigantic organ, dressed in a tutu.

These days, the records aren't selling in such quantities but they remain a hugely popular live act. Here, Clarke is dressed as an undertaker, while Bell's outfit could have been borrowed from Queen Victoria. And he is as preposterous as ever. "Does my bum look big in this?" he quips of his huge dress, before advising the audience to wrap up "because we don't want you going home sweating and half-naked".

Bell's Widow Twankie routine is bundles of fun, but Erasure's music is not the force it was. Once, they sounded perfectly, ever-so-slightly dated - rooted in the electro bounce of Kraftwerk and Clarke's previous band, Depeche Mode. Now, with the bulk of the pop scene moved on or mining the 1970s, Erasure sound out of synch. The age of the audience, and reception given old hits such as Stop! and Sometimes, suggest the duo have tipped over the precipice into nostalgia.

The pair are currently promoting a surreal covers album that has provoked critical mirth - although dipping into it here means that every song played is a hit, even if it is someone else's. Peter Gabriel's Solsbury Hill is intriguingly recast as a gay rite of passage - "He said, grab your things, I'm gonna take you home" - while an excruciating warble through Buddy Holly's True Love Ways could cause cats to die in the street. But most curiously, Bell's surprisingly moving vocals in Cliff Eberhardt's mournful Goodnight suggests that an unprecedented career volte face towards more serious, soul-baring stuff may offer considerable mileage. As it is, the former pop Titanics seem determined to go gradually down, having fun. Bell opts for a bustier and ends up topless, while someone shouts: "Give us a smile, Vince!" For the first time in the band's two decades, the frowning man obliges.

· At Barrowlands, Glasgow (0141-552 4601), tomorrow, then touring.