Suzanne Vega is out on the road with a work-in-progress sign hanging over her head. Her show consists mostly of the songs Vega supporters already know and love, but in-between she's sprinkling a batch of new compositions in various states of completion. With just a bass player called Mike, her guitar and wearing a black working-class-hero cap, she opened with Small Blue Thing and Caramel.

The first of the new ones was, she explained, "a song about a plant I used to know", and bristled with images of roots and pots as if she'd been swotting up on her Alan Titchmarsh. Another recent arrival is Edith Wharton's Figurines, and while Vega explained that inspiration can come from anywhere, you have to wonder how much creative mileage lurks in horticulture and novel-reading.

A third new one, Anniversary, was prompted by the 9/11 catastrophe, to which its melancholy folkiness seemed an underpowered response. She was more convincing when she stepped away from folksingerish dowdiness. A zooming bass and dramatic chords injected urgency into Some Journey, while Blood Makes Noise gained a stark immediacy from its voice-and-bass arrangement. Vega neatly exploited the overfamiliarity of Tom's Diner by using the audience as her accompaniment.

In support was Nerina Pallot, whose recent debut album, Fires, is highly polished. She confessed to being "very, very, very nervous", though you wouldn't have guessed. She's a capable guitarist, as she demonstrated on a touching new song called Grace, and better still on piano, where her technique soars beyond routine plonkiness. Idaho was powered along by an undercurrent of rolling, romantic chords, while Damascus sounded even better stripped of its recorded sheen.

Judging by the long queue to buy signed copies of her album afterwards, she'd made a big impression, though perhaps the willowy Ms Pallot's admission that her love life is "a sorry mess" had something to do with it.

· At St David's Hall, Cardiff, tonight. Box office: 029 2087 8444. Then touring.