Paolo Nutini, Royal Albert Hall

Earlier this week, when the line-up for Richard Thompson’s Meltdown festival was announced, one name in particular will surely have raised a few eyebrows: Paolo Nutini. Among the appearances by serious old folkies and earnest young Wainwrights and an “evening of political song” that Thompson has planned for his stint as curator of the annual festival on London’s Southbank, a show from this young Scottish singer and songwriter seemed a bit of a lightweight choice; perhaps even a controversial one.

With two hit albums to his name and a fascinating back-story – he was spotted when he made an impromptu appearance at a David Sneddon concert in Glasgow during a hiatus caused by Sneddon’s late arrival – Nutini has won a legion of admirers. But he has his detractors, too, chiefly thanks to his raspy throat, which seems to contain more gravel than the driveway of a stately home. Indeed, Nutini is a performer whose voice and mannerisms have inspired a compellingly derogatory Facebook page, I Hate Paolo Nutini, in which much bile is spilt on the subject of his voice, as well as his apparent inability to stand up straight on stage, and his general annoyingness. Some critics have tipped him for pop greatness; others can hardly bear to hear him sing without wanting to plug their ears. Intriguing.

Well, the second of two sold-out nights at the Royal Albert Hall gave some clues as to why Thompson might have chosen him. There is a rootsiness, an authenticity, to his music that’s refreshing in an age of manufactured plastic pop: he is a man who keeps it real. And as he demonstrated repeatedly during this show, stooping and twisting his skinny frame, knees knocking as he sang his heart out (also, refreshingly, in a Scots accent), his music comes from somewhere deep within him. The stomping jazzy swing of “Pencil Full of Lead” and the achingly lovelorn “Candy”, both from last year’s Sunny Side Up album, showed the breadth of his emotional range, while “Loving You”, from his debut disc These Streets, was a real old-fashioned soul belter.

So, all these things were good; also good was the vigour with which it was performed by his band of similarly skinny young bucks, plus brass and strings. And it was all certainly well received by the cross-generational audience. But there were times, it has to be said, when his voice grated, and I began to feel some sympathy for those Facebookers. He does tend to overdo the rasping buzzsaw thing, and needs to learn to hold back, rather than howling like a man who wants to be Al Green (fat chance) or drawling and bawling like an old Glasgow drunk.

And another thing: stylistically this show was a bit of a supermarket sweep, taking in jazz, ska, reggae, indie-rock, skiffle, folk, country and soul. And not all of them were done well. In particular, a rendition of Delroy Wilson’s "Riding for a Fall" showed that his voice really does not suit reggae. Which is not to discourage diversity, or to suggest that he should be pigeonholed as a singer of this or that musical genre. But there’s something almost indiscriminate about his eclecticism, and it leads inevitably to a sense that at times he is just dipping his toe rather than going in deep.

But when he gets it right, when he is in his element, he is a top man. “Alloway Grove” was a case in point: brisk, skiffly, heartfelt but not overbearing. And right at the end during the encore section he reined in his voice for a woozy, dreamy rendition of “Nature Boy”, crooning rather than croaking, singing rather than shrieking. There’s a lot to be said for a bit of self-restraint.

• More information on Paolo Nutini's tour schedule
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