Forget the Bedingfields - the Wainwright family is the ultimate musical dynasty, even if they are a little on the dysfunctional side.

Martha is the daughter of singer-songwriter Loudon Wainwright III and folk star Kate McGarrigle. She's also sister to Rufus, the crown prince of modern operatic pop. The latest star to arise from this sickeningly brilliant gene pool, she released her self-titled debut album this month, showcasing her rootsy, folky pop.

Of course, this will not be the first time she has wowed a Brighton crowd. She joined Rufus and a host of stars including Nick Cave for the star-studded Leonard Cohen tribute at last year's Brighton Festival, and supported her big brother at his headlining gig in October.

Yet although she's been familiar to those in the know for about five years, it has taken her quite a while to get headlining herself.

"No-one would sign me," she explains. "That is, there was no-one from a major label who I felt had complete confidence in me.

"Another reason is that I felt the last thing the world needed was another record. My father and Rufus are so prolific and we can't all be standing around at an instrument looking up into the sky for inspiration. I think that's why I have a tendency to wait for something to really bother me before I write about it."

It is perhaps unsurprising her family history might put Martha off, especially considering her bitterness towards the father who substituted the time he spent away from his kids on tour by writing songs like Rufus Is A Tit Man, Pretty Little Martha and First Birthday.

"For most of my childhood he talked to me in song, which is a bit of a s***** thing to do," she says. "As a result he has a daughter who smokes and drinks too much and writes songs with titles like Bloody Motherf****** A******."

Yet her musical destiny could not be ignored forever and, together with a bunch of mates and just a little bit of cash, she started to put a record together in her own inimitable style.

"It suited me to be underground," she says. "It suited my personality - maybe even the fact that I wasn't prepared to do the work and be as focussed as you need to be successful.

"There's one thing I can do which no one else in the family can do, which is rock. Rufus isn't very good at rocking out - it's like a joke when he tries to do it. But I like to get real sweaty, even if I'm not on electric guitar. I figure if you have four guys up there on stage, they might as well be playing their instruments, like, a lot."

Support comes from Johnathan Rice, a singer-songwriter and actor who plays Roy Orbison in a biopic of the late great Johnny Cash.

Starts 7.30pm, tickets cost £10/8. Call 01273 647100.