"I expected something out of this world," says a woman in the crowd, "but this is too danceable," and she inflects the final word as if unsure whether it's a complaint or a compliment.

Such is the mystique surrounding Richard James, aka Aphex Twin, intensely private, super-prolific twister of electronic music into alien shapes, that you want his new music to sound like nothing on earth - a terrible burden for any artist to bear.

Barely visible behind his laptop, James has an unenviable task. Metal-heads, jonesing ravers, electro-nerds and serious, Wire-reading types jostle in Barrowlands, a historic rock venue that's wrong for this kind of show. While there are plenty of people who have been dancing from the beginning, when the music is more about rupture than rhythm, there's an equal amount who seem bewildered, and a few perplexed customers yelling abuse at the stage.

For James, this set is probably comparatively unchallenging. He has been known to play sheets of sandpaper, and his sets supporting Björk a couple of years ago were a barrage of galvanisingly horrible, formless noise. He plays what might be an obscure Prince remix, the odd selection from his Analord series of 12-inches - basically old-school rave with an incredibly elegant sheen - and a less than charitable Streets cut-up in which Mike Skinner is made to say: "I'm really shit but oh my gosh I don't know it, I should absolutely be shot."

He also plays an enormous amount of breathtakingly beautiful music that could only very loosely be called electro. The audience are never quite sure where it's going - the first really big cheer is for a briefly surfacing Northern Soul horn riff, cast into the melee like a rope to a drowning man. Snatches of blissful melody bubble up and are pulled under, and the crowd surge and retreat, latching on to what they can.