In a world peopled by Jamie Cullum and Amy Winehouse, 32 could be considered shamefully old to release a debut album. London chanteuse Petra Jean Phillipson, however, is clearly no slacker; in addition to a 10-year career as a backing vocalist, she also holds down a day job as a member of the conservation team at St Paul's Cathedral.

Phillipson caused a minor stir three years ago as the husky-voiced siren fronting The Free Association, the house-punk project steered by DJ/producer David Holmes, who has since gone on to score Stephen Soderbergh movies. She has now returned with a debut album, Notes on Love, which is frequently startling.

Produced by former Verve guitarist Simon Tong, Notes On Love is a spartan yet compelling set of urban blues numbers dominated by Phillipson's soulful, Billie Holiday-like stylings. Facing an initially indifferent, sparse audience tonight, she proves that this soaring vocal performance was no studio trickery.

Flanked only by Tong and a backing singer, Phillipson looks like a riot grrrl but possesses far subtler musical mores. The brooding I Want the Impossible is a splendid torch lament, Phillipson breathing fire into the song's distracted reverie.

The clear-eyed One Day could be Cowboy Junkies, while the country-hued Nothing If Not Writing Time is a sultry, spectral yet earthy number worthy of Rickie Lee Jones.

Phillipson is clearly nervous, yet imbues her powerful material with an arch, alluring sensuality.

The short but powerful set ends with Tong's roots in the Verve showing as he collapses the final song into a satisfying welter of white noise and feedback. If she sustains this exciting promise, Phillipson's day job will soon be a thing of the past in more ways than one.

· At ICA, London SW1, on August 5. Box office: 020-7930 3647