It's over a week since Jools Holland announced the names of the albums shortlisted for this year's Mercury prize, and Zoe Rahman still can't stop giggling. "It's just, well, mad," she howls, huge billows of black hair cascading beyond her waist. "I kept saying, 'You're joking, right?' when they phoned to say I was on the shortlist. This sort of thing doesn't happen to the likes of me."
Last night, the 35-year-old pianist went along to play a gig with a Pakistani classical flute player at a London cafe, to be met by a big board outside announcing: "Mercury nominee Zoe Rahman". "I didn't cope with that very well," she sighs. "I mean, there weren't thousands of people but it creates a bit of pressure."
Her feet have barely touched the ground since she wandered innocently into the press conference announcing this year's shortlist to be hit by a barrage of flash cameras and banal questions ("I felt like Nicole Kidman"). Since then, her phone hasn't stopped ringing and she's been dealing with a succession of emails from people wanting to discuss "digital deals". "I've no idea what they're talking about," she says amid gales of laughter.
We talk in her music room - in reality a greenhouse in the shadow of Wembley stadium with Art Kane's famous 1958 picture of Harlem jazz greats on the wall, opposite a snap of Thelonious Monk. The day is so hot her piano has been swaddled in a protective duvet. The nomination, she says, is a "life-changing moment" in a career of perennial struggle for survival. When she looked at the entry form she didn't think she was eligible because there were spaces to fill in details of a manager, press contact, record company, agent and publisher. Zoe had none of these things, but she scraped together the £200 entrance fee and hand-delivered her entry.
That's the way it is if you're a British jazz act, she says, recalling the embarrassment of having to phone up people to try and get gigs and haggle over money. "I'd say, 'Hello, I'm Zoe Rahman' and they say, 'Who?' and I say, 'Oh, I play piano and I've got a band, can you give me a gig?'"
With a Bengali dad and a mum from Yorkshire, born in Sydney and raised in Chichester, Rahman has always felt an outsider. "I don't know many Bengali musicians, but it's obviously a big part of who I am. The only person I knew who spoke Bengali was my dad, and he never spoke it to us." She's been trying to learn Bengali in time for a trip to Bangladesh next week - partly a voyage of discovery into Bengali music and partly an excuse to party with 300 or so relatives. "I'm still on chapter seven of Teach Yourself Bengali at the moment. I've got a long way to go ..."
At school she played in a group with her clarinettist brother Idris, and at Oxford, where she was ostensibly studying classical music, Rahman ran a jazz club. "Classical just wasn't happening for me, but I'd go to jazz gigs and see people like Horace Silver and be completely bowled over. And I'd see piano players like Jonathan Gee, Julian Joseph and Jason Robello all leading their own groups, playing their own music and I knew that was absolutely what I wanted to do."
The album that got her to this point is Melting Pot, a warm and inclusive melange of piano virtuosity laced with subtle embellishments from different cultures. Rahman - who sheepishly admits she's a sucker for 1980s pop and says her favourite single of all time is George Michael's Careless Whisper - is pleased to find that in the Mercury contest, if nowhere else, she shares an even playing field with the likes of Arctic Monkeys, Thom Yorke and Guillemots. "I don't know anybody who just listens to one form of music. I don't feel the need to try and sound like Charlie Parker or anybody else, it's just me. I just want to make music that says something about me."
"People always say, 'Oh, I don't like jazz,' which is daft when most of them haven't heard it, and it's not like it's one thing anyway," she adds. "It would be nice to think the Mercury prize could lift the profile of jazz in this country. The musicians are enormously creative. It's not about marketing - it's about trying to be the best musician you can."
Five minutes after the Mercury announcement, Rahman had HMV on the phone ordering a couple of thousand more copies, and the 700 sales she has already made - mostly at gigs - will be dwarfed over the coming weeks. Last year Polar Bear, the jazz band led by drummer Seb Rochford, were nominated for Held On the Tips of Fingers and saw their sales rise five-fold from 2,000 to 5,000.
"Making the shortlist does help the musicians penetrate a wider audience," says Oliver Weindling, boss of Polar Bear's record label Babel. "The Mercury people are very helpful and you don't get treated as second-class citizens. Zoe Rahman has made an album the jazz world can be proud of. It's not all beards and sandals and gigs in the back of pubs."
Can Rahman go one better than all the other jazz artists nominated through the years - from Guy Barker to Courtney Pine, John Surman, Soweto Kinch and Polar Bear - and actually win the thing? Her gales of laughter suggest the answer is no. "I just want to do more gigs with my own trio and with other people. That's what it's all about for me, playing live," she says. "It would be nice not to have to worry about how I'm going to feed myself too."
· www.zoerahman.com. The Mercury music prize winner will be announced on September 6
