"I love tea," she says, opting for a herbal brew herself.

Her hospitality might also serve as a welcome distraction from promoting her forthcoming album, As I Am, which will undoubtedly be her most scrutinised work to date.

The quality of her previous two offerings, have ensured that the New York-born star's third album is one of the most eagerly anticipated of the year.

"I'm enjoying promoting the record at the moment, because I like to find the people I want it to get to," says Alicia, who, now the drinks have been served, is sitting on a sofa so huge she resembles a small doll.

"I'm so thrilled and proud and excited about this new music because it's better than anything I've done before. I needed to make this music and now I'm ready for people to hear it."

All told, Alicia Keys has come a long way from growing up as the single child of a single parent, in the then-rough New York neighbourhood of Hell's Kitchen. A long way, but not a long way - she still lives in New York, is still with the manager who discovered her as a 14-year-old singing and piano-playing prodigy, and is still chaperoned much of the time by her mum.

Even Bob Dylan is a fan. He namechecked her (twice) in the first verse of the opening song on his recent album Modern Times.

Saying her new album is better than her past two is some statement. Songs In A Minor and The Diary Of sold a combined 19m copies and won six Grammy awards between them.

But then Keys is nothing if not confident.

Schooled as a performer from an early age, she's the consummate professional. In an era of one-dimensional performers and over-groomed starlets, she has it all - virtuoso piano skills, the ability to write timeless songs and one of the best voices in music, contemporary or otherwise.

Love is a recurring theme throughout the album, and while Alicia is a little coy on the subject, she admits to having a tough time since her last record release. New song Superwoman was written about that heartache, when the 27-year-old was at her lowest ebb.

"I was so down back then, and I really needed to hear some positive reinforcement. I needed to know that even when I'm all a mess, I'm still a superwoman. It was for me when I wrote it, but now it's for every woman, daughter and child too if they feel the same as I did."

Keys will tell you only what she wants to tell you. To this day no one knows with whom she's in a relationship (she only recently conceded that she is in love), and rumours concerning her sexuality go unanswered. It's no big deal, but Keys' "don't ask, don't tell" policy increases the intrigue.

Away from music, Alicia is also carving out an acting career. She made her film debut in Smokin' Aces earlier this year playing a hot pant-clad assassin, and also appeared in The Nanny Diaries alongside Scarlett Johansson.

"I've been asked to do film for a long time, since the first record. But most people weren't very innovative, and they wanted me to play a kind of version of myself," she explains. "They'd say 'Alicia, why don't you do a Dreamgirls kind of thing?' That's cool, but I'd rather do something shocking and different."

She has also published a book of her own poetry, and she and her manager have launched a production company in partnership with Disney (Big Pita, Little Pita, which stands for "Big Pain In The Ass, Little Pain In The Ass"). They will develop family-oriented movies and TV series, some of them vehicles for Keys.

Her Hollywood ambitions run deeper still: this one-woman cultural whirlwind is also involved with an ongoing film project, produced by Halle Berry, about Philippa Schuyler, a mixed-race pianist (like Keys), whose life ended in a helicopter crash during the Vietnam War. It's the kind of remarkable biopic with which Keys might empathise.

As I Am was originally scheduled for 2006, but was cancelled due to family illness. In a rare moment of revelation Keys explains that her paternal grandmother - who had played a significant role in raising her - became ill with cancer.

She lived with Keys and the singer became her primary carer, partly, it seems, because Keys' dad, who had split from her mum when Keys was an infant, now lives in Colorado. It was a long, painful decline over most of 2006.

Keys abandoned all plans to make the new album. And, as she took the most time off since starting out in the music industry over a decade ago, she realised she'd neglected her personal life in her relentless drive to succeed.

"That's exactly what it was," she says. "That's why I had to totally, completely stop. I'm used to constantly going on to the next thing, but I realised at that moment, 'Man, this is it, this is all I have'."

"If I hadn't devoted all that time and energy to my grandmother, I would be a terribly messed-up person right now. I would be full of regret and really down on myself for that.

"I was able to spend some of the most precious time with her ever. And I grew. And grew up. I learnt a lot - about family, about who's there for me, who's not.

"It was a whole different lifestyle for me. Before I was, 'Oh I have to go to Miami? OK, I'm just gonna hop on a plane tomorrow'.

"It was very stressful and it was very hard on my spirit. And I was obviously totally saddened by the fact that eventually, you know..."

She stops and gathers herself. "So it was hard, and it was joyful. It was bittersweet."

As if movies and music were not enough, Keys is also an active philanthropist, carrying out work on behalf of a number of organisations, including Keep A Child Alive, an Aids prevention charity operating in Africa, as well as spelling is correctFrum Tha Ground Up and Teens In Motion, who both provide education opportunities for underprivileged children in America.

"I feel there's emptiness in the world," she says of why she chose to get involved in such work. "We're all searching for something, but no one knows what, and no one is talking about anything. Nobody's saying anything that's important, and there are all these big issues, but my generation is so far removed from them."

So does she consider herself a role model?

"I don't know what a role model feels like," she ponders. " But I am very conscious of what I say and do. I don't think it's that big a responsibility - it's just about trying to be a good human being."

› Alicia Keys' third album As I Am is released tomorrow.