Whether a neatly contrived piece of pantomime or a serious musical endeavour, The Polyphonic Spree are one hell of a sight. Dallas's self-styled "choral symphonic pop band", a 24-strong ensemble led by the charismatic Tim DeLaughter, take to the stage in white robes, their only nod to individuality being the tips of their shoes.

Blending the psychedelic barminess of The Flaming Lips with the euphoric intensity of Godspell, they're 21st-century rock's answer to the Moonies. In an industry dominated by dour indie bands and sneering rock quartets, theirs is a show like no other. Tonight's atmosphere has more in common with that of a Pentecostal church than a serious rock gig.

The Polyphonic Spree could be written off as a novelty act were it not for their gloriously chaotic sound. Flutes, French horns, trumpets, trombones, cellos, violins, kettle drums and a six-person chorus all battle for our attention. Their songs come with uplifting choruses and roaring crescendos that make your head spin with delight. By the end of their set, the feelgood factor has gone off the scale and the band are throwing themselves on each other in delight.

The Datsuns are part of the much-trumpeted "new rock revolution" even though their sound is as old as the hills. The New Zealand four-piece wear their influences – AC/DC, Motorhead, early Aerosmith – on their sleeves and, with their pouty grins, pointy shoes and drainpipe jeans, they certainly look the part. Their songs, all howling vocals and big, blasting riffs, provide a quick rush of blood to the head though, like all the best highs, it doesn't last. While it's good to see a new generation appreciating dumb-ass rock'n'roll, when all's said and done, AC/DC do it a lot better.