If you've ever, for whatever reason, wondered what it's like to feel ancient, then just take a look at the charts. Britney, Christina, Destiny's Child, little Justin Timberlake from N'Sync are all on the cusp of their twenties, yet already multiplatinum selling artistes. Similarly youthful but with less broken sales records to her name is self-styled 'moody cow' Thea Gilmore, bringing a breath of fresh, sexy air to the Musician, a venue typically frequented by musos and real ale enthusiasts.

Accompanied tonight, as for the rest of the tour, by guitarist/vocalist Nigel Stonier, Thea ploughed her way through an all-acoustic set of old faves from 'Burning Dorothy' and 'The Lipstick Conspiracies' (the latter recorded when just nineteen), as well as current album 'Rules For Jokers'. Interspersed are witty remarks about the décor and some cracking covers: a version of the Buzzcocks’ 'Ever Fallen In Love (With Someone You Shouldnt've) is played slow and straight, turning the punk classic into a heartfelt declaration of unrequited yearning. And straight out of the left field is a guitar-fuelled 'Straight Up', Thea making the schlocky 80s Paula Abdul hit sassy and cool.

But it's her own songs that shine the most. 'Rules For Jokers' may be her unplugged album, but that doesn't mean that at the grand old age of - um - 21, Thea has mellowed. Nope, not one iota - in 'The Things We Never Said' from '...Jokers', she gives a vitriolic kiss off to a former lover, delivered tonight with spleen and candour that would make Alanis Morrisette blush. And no, the comparisons between Thea and the long-winded one are far from valid; Gilmore's lyrics often deal with societal issues and occasionally lapse into storytelling, some way from Alanis' neuroses and histrionics.

She's more like a home-grown Ani Difranco, caustic, fiercely independent, and with protest songs that Joan Baez would give her eyeteeth for. Case in point is 'Generation Y?', a cutting analysis of post-millennial apathy and self-obsession, bolted to a tune catchy enough to be A-listed on Radio 1 for as long as it takes for you to want to gnaw your own genitalia off rather than hear it again (not that you ever would, it's a good song....) But the actual next single is 'Saviours And All', which unfortunately fits the bland, polite, homogenous female singer-songwriter pigeonhole a little too snugly - unlike, say, a vehemently performed 'Seen It All Before', it doesn't have Thea stamped all over it. But then methinks a song apparently written from the point of view of a jaded ex-prostitute wouldn't exactly fly off the shelves (call me cynical, but....)

Highlights of the night are the lilting lullaby-like 'Holding Your Hand (quietly reminiscent of Green Day's 'Good Riddance', of all songs), the us-vs-the-world mentality of 'Inverigo' and the aforementioned Buzzcocks tune. Despite proclaiming that she doesn't believe in 'all that encore crap - it's bollocks', she does the customary walk-off, walk-on, returning on her lonesome for a mesmerising, confessional 'See If They Applaud'. Nigel rejoins her for a blunt, assertive 'People Like You' and a revelatory run through 'Lean On Me'.

Even though Thea played a strong 16 song set, to her credit she could have chosen 16 more songs, all as accomplished and finely crafted as the ones she performed tonight. And with three albums already under her belt while only just being able to stand for parliament or rent a hire car, she's bound to join the Beyoncés of this world before the decade is out. Hell, she's got my vote.