With the endorsement of Elton John and a name that sounds like an Eton schoolboy, Rufus Wainwright should not, by rights, be perched on the cutting edge of cool. Yet this Canadian folk-pop enigma, lauded as the most original songwriter of his generation, has emerged as a darling of the music press and the hottest property on the London celebrity scene.
But the friendship of Mark Gatiss and Sam Taylor-Wood does not a profitable artist make, so with a UK tour extended to 14 dates and the backing of a publicity machine that also supports Madonna, Wainwright hopes to extend his reach beyond the knowing metropolitan sophisticates.
Opening with a six-minute setting of the Agnus Dei is probably not the best way to go about gaining mainstream appeal, but this is the self-contradictory Wainwright all over. The piece also opens his fourth album, Want Two - a companion to Want One - and is either stupendously brilliant or hopelessly self-indulgent; possibly both. Certainly, it shows off his astonishing vocal range, impressive on recording and awesome close up. Wainwright is a dangerous performer, warning us the night would be "loose" - and had he missed any of his soaring notes by even a shade, his powerful, reedy voice would have pitched into an ear-shattering wail.
Much of the rhapsodic melancholy that infects Want Two and dominates this performance would barely make the playlist of BBC's Radio's 6 Music, let alone Radio 2. All the same, every great artist has a "No 1 record" in him somewhere: Wainwright's is Cigarettes and Chocolate Milk, a tormented anthem to his well-documented past addictions that is among the best-received of the night. Happily, Rufus the Rocker comes out of the closet with Birthday Girl, demonstrating he has a roof-raising side to his fey demeanour.
There's no doubting Wainwright's ambition: "Rufus for Pope - there's a vacancy," he muses. But if anything, he is on a path that is taking him further from the mainstream success that he professes to crave.
· At Hall for Cornwall, Truro (01872 262466), on April 5. Then touring.