Even prisoners get offered a glass of water. Alas, this was not a privilege extended to the initially excited but soon cramped and parched crowd who sweltered under television lights for 90 minutes without access to sustenance as Kanye West, America's pre-eminent post-Eminem rapper elected to join us in his own time, rather than at the promised one.

This show was mostly a competition prize to celebrate next month's release of Graduation, the 30-year-old's third album, but once a headphones-wearing man emerged to tell us how to clap, it was clear the audience were merely unpaid extras in a show to be broadcast on Channel 4 (2pm, 2 September).

Yet this son of a lecturer and a Black Panther has not risen without good cause. Wearingly, Jay-Z's protegé may have his own record label and fashion line, but much more interestingly he's sufficiently broad-minded to collaborate with Coldplay and emo-rockers Fall Out Boy - and he famously told his country that "George Bush doesn't care about black people" in the wake of the Hurricane Katrina fiasco.

Atrocious sound and television lighting notwithstanding, West still overturned the notion that live rap cannot work - and not merely because he was accompanied by a brilliantly styled female orchestra, who played little but looked fabulous.

Bounding straight into the opening I Wonder like a ravenous hyena, the thoughtfully charismatic Atlantan proved to be the anti-rapper. There was the occasional gust of hot air, such as Champion with its refrain of "Tell me what it takes to be Number One", but such hubris was leavened by a spot of piano playing and myriad monologues which seemed to tell his life story.

And there was musical depth in the super-taut Diamonds From Sierra Leone, though the song had to be stopped halfway through for West to teach the audience how to make diamond-signs with their hands, "so that it looks good on television". West's priorities were not universally appreciated and when the song was re-started, some diamond signs looked suspiciously like the internationally recognised hand signal for masturbation.

Finally (after I Wonder was reprised without explanation other than a brusque order to "act like it's the start of the show") came the irrepressible Touch The Sky and, as neither side wanted an encore, West's parting shot of "I love you".

Nobody believed him for a moment, but, nobody doubted that for all the evening's frustrations, Kanye West is the real deal.