The first thing you hear on the Belles' new disc, Omerta, is the sound of multi-tracked voices harmonising rather artfully. It sounds great, but unfortunately onstage the trio are dependent solely on Chris Tolle's pleasant but one-dimensional singing to carry the weight.

This is one of several paradoxes about the band. Some of the time they look suspiciously like singer-songwriter Tolle with a couple of backing musicians, especially when the other two leave the stage and let him do his guitar-troubadour thing. Sometimes they hark back to nerdish 1960s units like Peter and Gordon in their air of studious self-absorption and lack of any sign of rock'n'roll extravagance. And sometimes they sound like a psychedelic experiment from the West Coast, but one which has had all the special effects and overdubs removed.

Certainly the steam-bath heat wasn't doing them any favours, since it was a struggle merely to remain conscious, let alone remember words or play an instrument. Tolle kept thanking us for being a good crowd, but by the end of their set it was more of a gaggle, since people had been slipping away steadily for the past half-hour, probably in search of an oxygen tent.

Much of the time I found my attention gripped by drummer Jake Cardwell. With sweat flying off him like a dog drying itself, he maintained a crisp, unswerving beat. Despite all his labours, three Belles isn't quite enough to get their point across. When Tolle sings a piece like Never Said Anything, with its cascading chorus and keening melody, you get a sense of what they're capable of, but it blossoms more luxuriantly on disc.

Likewise, Victory Parade is a little like one of the Jesus and Mary Chain's suspended fuzzbox reveries, but without the fuzzbox it's inclined to drag instead of float. Me, I'm off to play the CD again.