Who the hell is Paolo Nutini? The facts are well enough known by now. The 20-year-old singer and songwriter from Paisley in Glasgow has sold more than 720,000 copies of his debut album, These Streets, since it was released nine months ago. He has performed in the smallest clubs and the biggest stadiums (supporting the Rolling Stones). And he has amassed a fervent, predominantly female, following.

But his musical identity is a lot harder to pinpoint. Just when you think you have him pegged as a lovelorn ballad singer, perhaps, or a blue-eyed soul star, or a mainstream pop-rocker, or even some kind of Richard Hawley-type retro songsmith, Nutini shapeshifts into another musical guise.

At Brixton his show began with a blaze of sound and light. As multiple copies of his name swirled around on a screen at the back, and orchestral theme music blared from the PA, you half expected Bruce Forsyth to come on and ask us to give Nutini a big old Brixton welcome.

The bushy-haired kid in the plain brown leather jacket who then appeared, together with his unshowy three-man band, could not have looked less like an heir to the light-entertainment tradition. As they pushed off with the breezy shuffle of Alloway Grove, Nutini adopted a classic indie-kid pose, slightly stooped with one hand on the microphone stand to steady himself, focusing all his energy on the song rather than making a show of “entertaining” the audience.

But entertain us he did, with a string of romantic songs, some of them, such as These Streets and Autumn Leaves, presented with an unbelievable gentleness of touch given that he was facing the huge bear pit of the Academy. With each number, a different contour of his remarkable voice was revealed. Its default setting was a firm, slightly serrated tenor. But Million Faces brought a lovely falsetto chorus. Applying a tougher, more careworn touch to Moby’s Natural Blues, he followed it with Last Request, a delightful, old-school soul song that could have been written by Macy Gray. Rainbows and Jenny Don’t Be Hasty were the closest he came to a traditional rock performance, but even with these he never allowed himself to get sucked into any of the time-honoured performance mannerisms.

As if to emphasise the range of material at his command, the encores produced an unexpected version of I Want to Be Like You (the King Louis song from The Jungle Book), followed by a very Glaswegian-sounding country shuffle called Funky Cigarette. Whatever else he might be, Nutini is not your average pop pin-up. Tour continues in Plymouth tonight

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