She walks on stage looking pale and enervated, like a ghostly image of heroin chic. Just what have they done to Thea Gilmore? Then two songs in she reveals she’s “got the lurgy, big time”. It turns out she’s been taking nothing stronger than herbal tea to keep the flu at bay. Music proves an even more potent drug, however, and her energy returns as the songs from current album Avalanche work their magic on both her and us.

Backed by a four-piece band, a rocking “Have You Heard?”soon has the corpuscles racing again, and reminds us Gilmore is far more than just another long-haired girl with a guitar. She can do the acoustic schtick as well as anyone, as she shows on the lovely “Holding Your Hand”from 2001’s Rules For Jokers. But she’s also got some cracking pop tunes, as she proves on “Juliet”. Older fans nod in approval at “Mainstream”, a kind of cross between “Subterranean Homesick Blues” and “Rockin’ In The Free World”.

“Mud On My Shoes”, from the limited edition CD Songs From The Gutter, is a country blues (“except in the Thames Valley we call it clinical depression”). “Avalanche” is dedicated to the bravery of The Dixie Chicks (“Who’s going to be able to stand after this avalanche?”), and an impossibly poignant “Pirate Moon”to the memory of Elliott Smith. Then there’s a terrific cover of Creedence’s “Bad Moon Rising”, which she introduces by observing, “If my generation was listening, this is what I’d be whispering to them.”

And that’s Gilmore’s only problem: many of those listening are drawn from her parents’generation. Yet it’s a misconception to imagine she’s some old-style hippie troubadour, and when she comes out from behind the comfort zone of her acoustic guitar?which she did for almost half the show?she shakes and shapes just like the real pop star she deserves to be.

If this sold-out tour has seen Gilmore come of age, it’s clearly had a similar effect on her support act, Adam Masterson. Accompanied only by his acoustic guitar and an electric bass, his voice has taken on a gloriously rich, sandpapered quality only hinted at on his debut album, One Tale Too Many. After the show, we inquire if he’s another flu victim. But it seems the new depth to his voice is simply a natural result of getting a few gigs under his belt. Forget the likes of Pete Yorn and John Mayer. In Masterson, we have a homegrown talent who wipes the floor with the lot of them.