A good half-dozen vocalists have passed through the career-development lab that is Zero 7 (the dance act also known as producers of soft-furnishings pop to discerning yuppies). José González is the best-known, but Sia Furler is the most paradoxical: an Australian with the gauzy voice of someone emerging from a trance, and the personality of, well, on her website she reminisces about "being born out of the butthole of a unicorn called Steve" and on stage, she is an amiable ladette, passing beer to the crowd and exchanging smooches with a smitten chap in the front row.

Both sides are in evidence at this show, which is packed with people who already know her yet-to-be-released third solo album, Some People Have Real Problems. "It has been leaked online in Transylvania and Mexico," she says sardonically. Not that she is complaining: "I'm getting pretty successful now, but it is scary, 'cos I could turn into a wanker." She is referring to the intense ballad Breathe Me, which has opened doors for her by popping up on both Grey's Anatomy and Six Feet Under, and reduces tonight's audience to fluttering adoration when she sings it.

Sia is as much a raconteur as she is a singer, and her slow-to-blossom seven-year career is a subject she returns to several times. The Co-dependent, which quiveringly recalls Portishead, was inspired by being dropped by her last label for making a too-pop album ("They said, 'Your fans won't like it,' and I said, 'What fans?'"). Later, after a tremendous, glacial performance of Sunday, she reads out a list of fans' names that she has painted on her arm: "I read what you guys say on my messageboard when I have a low- self-esteem day, which is every day," she explains. She is Dido with attitude - one to watch in 2008.