Kate Nash could not be more "now" if she had been invented by MySpace geneticists. Her vintage dresses, breathless blog and peevish tunes are so on-the-money that the Calvin Klein people must have had her picture on the wall while they were concocting their new "technosexual" perfume, In2U. Having followed the now-standard route of putting her songs on MySpace well before a record deal beckoned, she acquired 25,000 online admirers, along with the interest of every major label. Nash is apparently about to give up doing it herself and sign an old-fashioned recording contract, but that has to be a good thing in terms of wider exposure for a repertoire that includes Shit Song and Dickhead.

But is she any good? Happily, yes. Lo-fi by nature and budget, Nash shoulders most of the burden on stage, playing keyboards and guitar, and tweeting in an accent that swoops from north London to Mayfair. She is flanked by a drummer and a keyboardist/ laptop-twiddler, who add a bit of flesh to what would otherwise be rather skeletal songs. But it is evident that she could see it through without them - and at this point, it is impossible not to mention Lily Allen, who, a year ago, was playing the small rooms Nash is now touring. At the equivalent stage of her career, Nash is already more accomplished, with a larger bag of musical tricks up her sleeve which will serve as a handy fallback in the event of a bad-mood day: tonight she unveils bits of indie-pop, cracked folk and piano-pounding blues.

The mood is buoyant ("This is my first-ever UK tour, and it is really, really fun") and the attitude minty-fresh. Although she is not above belittling ex-boyfriends (that will be the "Dickhead", then), Nash is essentially an inquisitive 19-year-old whose London cynicism is only a veneer. Underneath is a wellspring of chatty confidence - she originally trained as an actor - and a remarkable ear for dialogue. The latter has been parlayed into story-songs such as Mariella, whose 10-year-old hero will "never, ever, ever, ever" do what her mother says, and Birds, a boy-girl duet in which she takes both roles. Catch her while she is fresh.

· At Night & Day, Manchester (0161-236 4597) tonight. Then touring.