Everyone is talking about Sia right now. But the only one who seems surprised is the woman herself.

With her emotive vocal performances and captivating song writing, the Australian born former Londoner, has seen her reputation explode in her adoptive USA - not through cynical marketing, but good old-fashioned word of mouth. and it's modern equivalent, YouTube.

The face-mangling video to her tune Buttons, is the second most watched music video in the site's history - and has led to a wave of parodies.

Though still best known here as the silky voice of Zero 7, Sia Furler is a must-see solo act across the Atlantic.

And her rise to fame was done no harm at all when her shudderingly beautiful Breathe Me was chosen to soundtrack the climax of hit TV series Six Feet Under.

It's clear that Sia's star is most definitely on the rise. Yet, as she is quick to point out, three albums into her career, the success predicted for her, has been a long time coming.

"After all these years of trying, the second I stopped worrying about being a success, I got successful.

"I realised that I'm a credible person and that I don't care what demographic I appeal to any more. As soon as I stopped trying, I suddenly became cool and credible and started attracting all these really cool people like Kirsten Dunst, Ryan Gosling and Beck."

Sia's journey started with her "bohemian" Australian childhood. She first sang in her parents' rockabilly band, The Soda Jerks, before joining jazz-funk band Crisp at 17.

"We thought we were really cutting edge," she says, "but we were trying way too hard."

After three years fronting Crisp, Sia bought an open-ended, round the world ticket. She settled in London, scored a Top 10 hit with her first single, Taken For Granted, and in 2001 released her debut album, Healing Is Difficult.

But a week before arriving in the UK, the man she describes as her "first true love" was run over and killed by a cab in Kensington High Street.

"Nearly everything on the first album was about that," she say.

"I was pretty messed up when Dan died. I couldn't really feel anything and, as a result, Healing Is Difficult was a very deflective album. It was me not dealing with stuff.

"The second album, Colour The Small One, was the opposite. I'd bottled all this stuff up. I felt suicidal."

With the success of Zero 7 in America, she moved to LA in 2005, where she shared a house with The Strokes' drummer Fabrizio Moretti, before moving to New York's trendy SoHo.

Her new album, the knowingly titled, some people have REAL problems is acknowledged as her best so far. So is it the sound of Sia finally moving on?

"Not really, or at least I think so," she says. "This album isn't really autobiographical. You don't have to have a crazy life to be able to write these stories.

"I mean, I'm so much better now. But then that's what having a good therapist does for you."

And the album title? "It was a joke when we were recording. We were having really bourgeois problems, like traffic and bad coffee - we had to keep reminding ourselves that some people have REAL problems, like not having a mum, or legs.

"Seriously, life's so good right now. My apartment's bigger than Madonna's house, and I'm getting pretty rich and pretty famous.

"So the title's a reminder to me, not to get too carried away."

Sia plays the Carling Academy tomorrow. Tickets are £14. Support comes from the mighty Har Mar Superstar, so get there early!

New single The Girl You Lost' is released on April 21.