Way Beyond Nashville, the annual celebration of Americana, is now in its third year and, with events taking place across London, more sprawling an operation than ever. Still, the three-woman line-up at this opening night concert gave some idea of the festival's elastic, hard-to-define scope.

Opener Martha Wainwright is the daughter of Loudon Wainwright and Kate McGarrigle, and her strident delivery and willingness to bend the parameters of tunes and guitar tunings suggest she's well aware of the challenge of living up to her illustrious parentage.

Next up was Canadian singer-songwriter Suzie Ungerleider, who trades under the name of Oh Susanna. This can have the unfortunate effect of making you think she's a rock band, an impression reinforced by the hefty squad of musicians who play on her latest album (also called Oh Susanna). Accompanied here by just keyboards and drums, she blasted through a compact set that enabled her to show off the raw power of her voice, an instrument forceful enough to mask the primitiveness of some of her material. Her best songs, especially Carrie Lee, mix simplicity with strong melodies, though her version of Dylan's I'll Keep It With Mine is a reminder of the layers of ambiguity her own songs lack.

Mary Gauthier comes from Louisiana and pronounces her surname "Go-shee-ay". She used to run the award-winning Dixie Kitchen restaurant in Boston, but sold it to pursue a career in music. She probably overheard a few stories during her Kitchen years, and her songs - and the comical spoken narratives with which she introduces them - are crammed with love and loneliness, faith and its loss. Her characters are strippers, drag queens and derelicts, and the picture isn't always pretty ("I co-wrote that one with Edgar Allan Poe," she says), but Gauthier's performance evokes a lust for life that is never going to settle for risk-free security.