Alicia in chains: The truth behind R&B's most secretive star

While Jennifer Lopez's people arrange candles in the dressing-room next door, I'm waiting to pray with Alicia Keys. The singer-songwriter and multimedia entrepreneur is not praying that her new album is well received. Keys, 27, has been so stonkingly successful at everything she has turned her hand to – music and beyond – that no celestial intervention will be required to kick-start the campaign for As I Am. She has sold more than 20 million copies of the album's two predecessors, 2001's Songs In A Minor and 2003's The Diary Of Alicia Keys, and won a boatload of industry awards, including nine Grammys. Keys songs such as "Fallin'" and "A Woman's Worth", supreme examples of genre-transcending nu-soul and R&B, are modern standards.

She was impressive, too, in her debut film role, playing a hitwoman in Smokin' Aces, a thriller released earlier this year; she underlines her range in this month's The Nanny Diaries, a feel-good family movie in which she appears alongside Scarlett Johansson. She has 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.

Even when she is not working, Keys is still working: she has supported voter-registration drives in the US, performed in the House of Commons (her host, the Tottenham MP, David Lammy, viewed her as an important role model for his young black constituents), and is active – properly, boots-on-the-ground, fingers-in-the-dirt active – with a range of child-oriented charities in the US, Africa and Asia.

All told, she 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 has noticed Keys: he namechecked her (twice) in the opening verse of the opening song on his recent album Modern Times: "I was thinking 'bout Alicia Keys, couldn't help from crying/When she was born in Hell's Kitchen, I was living down the line/I'm wondering where in the world Alicia Keys could be/I been looking for her even clean through Tennessee."

Tonight in New York, we're not far from Hell's Kitchen. Keys and her team have been stuck in her airless dressing-room – number 303, aka " Diamonds" – in the bowels of Radio City Music Hall for seven hours or so. Keys likes to lead her band and crew in prayers before each performance. However, it seems that their stage-call may still be some time away...

The occasion is the fourth annual Fashion Rocks charity extravaganza, a televised fusion of style, music and tardiness held during New York Fashion Week. Keys is due to perform a track from As I Am, and to climax the show with a duet with Carlos Santana.

She has done a lot of these high-powered duets, with superstars such as Bono, Stevie Wonder and Jamie Foxx. Does she ever get nervous? "Mm-mm," Keys says, with ' a shake of the head. "I just soak up the good energy. We're not competing, but reinforcing each other. There's nothing wrong with a little healthy competition, but I don't need to worry about that."

A few weeks earlier, Keys had come to London to perform some new songs, by way of introducing As I Am to a small gathering of the music and media industry. Two of the songs, "Thing about Love" and "Sure Looks Good to Me", were written with Linda Perry. She's the diva doctor: the mouthy former frontwoman of one-hit wonders 4 Non Blondes, who has produced hits for Christina Aguilera ("Beautiful"), Gwen Stefani ("What You Waiting For?") and Pink ("Get The Party Started"). James Blunt is also, to some extent, Perry's fault, since she signed him first, to her own label, Custard.

Perry, the queen of radio-slaying pop-rock, was a surprising choice for the R &B-loving Keys. When we met on the roof terrace of a nice hotel the day after her London showcase, I asked Keys why they had collaborated. " Well, you know, it was something that was just natural. I've always admired her work. And I really admire the honesty of her work. At this time in my life, I was starting to realise that the answer to a lot of my personal issues was an [increased] state of directness. I was so used to being hidden behind this wall of emotionless [sic] that one would never be able to quite tell, 'What is it about her?'. I was getting so good at being able to 'turn on' that I realised I was destroying myself in the process, and becoming dehumanised."

I know what she means. Prior to this year I had interviewed Keys in London and New York; I also travelled to China with her when she performed on the Great Wall. On all occasions she was the picture of courteous but steely professionalism. The work was what mattered, nothing else. It was hard to imagine her letting her hair down.

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. Plus, in this day of wall-to-wall celeb overkill, camera phones and " sources" flogging secrets to the insatiable gossip mags, the fact that no one has ever "caught" Keys with anyone is pretty incredible. Imagine the pressure to keep things quiet. Surely that's no way to lead a healthy relationship?

During our first meeting, after I thought I had noticed her acting cosy with Kerry "Krucial" Brothers, her longtime song-writing partner (they also write for other artists), I asked Keys whether she was going out with him. Her response would have shamed Medusa. And I was none the wiser.

More confusing still, she seemed aware even back then that she radiated an air of robotic aloofness – as she told me in China, if she were to write a song about herself called "Painted Smile", it would be entirely appropriate. "Right!" she laughs when I remind her of this. " I finally realised, 'Alicia, Jesus, your problem is that you are not being honest enough with anyone, and especially not yourself. You need to be that direct to come out of this place where you're suppressing so many emotions.' At the point of realising that, I was really looking for support of that directness. And if there's one thing that Linda Perry is, she is unafraid to be who she is. She's ballsy."

Perry is also – loudly and proudly – gay. As was the assassin Keys played in Smokin' Aces. Then, when I hear her comeback single "No One" for the first time, I note the lyrics: "People keep talking/They can say what they like/But all I know is everything's gonna be all right". So, putting two and two together and coming up with 40, as two ladies attend to her hair and make-up in Radio City Music Hall, I ask Keys for the inspiration behind the lyrics to the comeback single. The answer is another elegant fudge: Keys' inspiration was "any great relationship that I have and the way that people try to break apart. And the way that people see a good thing and become envious of it. But still, through all of that, no one is able to break it when it's a true bond, whether it's with your wife, husband, boyfriend, daughter, son, sister, your family, whoever." The only significant relationship she didn't mention being, of course, girlfriend.

I try another tack. How will her attempts to be more honest manifest themselves? Keys replies that she is trying to temper her workaholism. Fine, but will she continue to keep her personal relationships secret? "Yeah. Somebody said this to me in London – 'How can you be so personal on a record and not be telling everyone everything all the time?' And it's tough to balance, actually. I do want to always be honest about what I'm feeling and be able to feel what I say, and not hide it. But at the same time, it is a balancing act to not give everything away so people, such as yourself" – and here she flashes a laser smile – "can run with it and disrespect it. So I'm not sure. I'm figuring that part out. I don't have all the answers." That's that cleared up then.

Outside Radio City Music Hall, the Fashion Rocks excitement is mounting. Whole Manhattan blocks have been sealed off by buses from the NYPD's communications division. Out front, amid honking traffic and dragoons of giant security guards and tubby coppers, a busy lady with busy hands is saying into a cellphone: "Hi, this is Kim, Jennifer Hudson's talent escort. She's looking for some towels..."

Earlier this evening, Keys had left the venue by one entrance so she could re-enter via another. The latter is the entrance with the red carpet and phalanxes of paparazzi, TV crews and online reporters. Keys walks arm-in-arm with Francisco Costa, a dapper little man with braces on his teeth. He's creative director at ' Calvin Klein, the 2006 womenswear designer of the year, and the chap who dreamt up the fabulous gown Keys is wearing.

I follow close behind. Keys works the media like a pro, slowly schmoozing her way up the line of microphones jabbed at her over the crash-barriers. The flashlights and spotlights are blinding, and so are the bling and dentistry of the celebrities who follow in her wake. Skinny gals Jennifer Alba and Mischa Barton! Muscled hip-hoppers 50 Cent and LL Cool J! Looking good for your age, Teri Hatcher! Fashion dowager Anna Wintour! Someone who I'm told is designer Michael Kors! "Kimora!" shouts a TV crew at Kimora Simmons, star of the E! Channel reality show Life In The Fab Lane and ex-wife of music mogul Russell Simmons.

Now Keys is standing in the centre of the red carpet talking to Gayle King. King is Oprah Winfrey's best friend, and editor-at-large of the chat-show queen's O magazine. Out of earshot of the slavering media pack, two of the most powerful black female cultural figures in the US are talking about Africa and their last visits there: Oprah has opened a school for girls near Johannesburg; Keys is helping fund a clinic in Durban. She's bought the building and is currently seeking further investment.

"It takes a coupla million dollars to create the type of facility that would really serve the people the best," she had told me earlier. Last year, under the auspices of the Keep a Child Alive organisation, she undertook a "pilgrimage" across Kenya, Uganda and South Africa, visiting churches, schools and community centres.

"I saw kids, [aged] 13 or so, doing these elaborate plays about the Aids pandemic. This was the way to spread the news. It was funny, it was quirky, it was young people speaking to young people, and it was a way to really educate people about how [infection] happens."

Back on the red carpet, time is ticking away – it's been 40 minutes since Keys left her dressing room. Now she's returning to it. Inside, all is quiet once more. Stultifyingly so. Keys and co have been here for eight hours.

Finally, it's time to pray. Musicians, backing vocalists, management, " glam squad" (stylist, hair, make-up), record company and me – arms around each other's shoulders and eyes closed – are encouraged by Keys to "breathe in the good stuff and exhale the negative stuff". Then we chant as one: tonight's performance is "not for us, Lord, but for you!"

For the quietly devout Keys, that is no doubt true. But tonight's performance – which, when she finally gets on stage, lends some much-needed pizzazz to a bill featuring Linkin Park and him out of Nickelback – are also about kickstarting the huge, international promotional campaign in support of As I Am. When you're an international superstar, nothing must be left to chance.

A scant few hours after Fashion Rocks gasps to a close, Keys and her party of 30 fly to Las Vegas. Keys tops the bill at the MTV Awards, completely outgunning Britney Spears and her now-notorious , thoroughly dismal comeback. Keys presents a svelte, sexed-up look – she's been known for being coolly prim up until now, which was itself a blessed relief when all around her in the R&B world seem engaged in a perpetual contest to wear the least clothes and strut the most suggestively. She begins alone at the piano playing "No One", a gospel-flavoured belter. Then, as the curtains draw back to reveal a choir, Keys segues effortlessly into a rendition of George Michael's "Freedom". It was some show.

Keys is great at projection. It's hard not to be wowed by her stage, video and interview performances. She's more hospitable and more chilled than most 20 million-selling megastars. But what lies behind the shine and the smile? Where's her interior life? As I had discovered when asking about her personal relationships, even with the new honesty she claims runs through her new record and her new "self", Keys can't quite give up absolute control.

Yet there was one subject about which she was candid. Speaking to the small audience in London – and, later, in the American press – Keys talked about how, prior to writing and recording As I Am, 2006 had been a year of " real lows". Questioned on this, she blathered something about these being in the area of "personal growth" and how the illness of a "close relative... broke me down in a lot of ways".

When I (respectfully, I hope) later press her on this point, she eventually says that her paternal grandmother – who had played a significant role in raising Keys – became mortally 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 a 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, her autopilot loquaciousness faltering for once. "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 she hadn't devoted all her time and energies to her grandmother, "I would be a terribly messed-up person right now. I would be full of regret and really down on myself for that. And 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.

"I mean, 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.' Even if was able to go to the studio, I had to leave by 11." I think she means 11pm, which tells you a lot about what Keys views as a short working day. "It was a whole different thing for me," she continues. "And 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"

Earlier this year, Keys finally began to work on the songs that would comprise As I Am. She'd been through death and pain and – cliché alert – come out fighting. The songs on her third album are, for the most part, all the better for it: uplifting, loose and powerful. If and when she completely relaxes about her personal life too, she'll be unstoppable. And, perhaps, be able to have a lot more fun.

' As I Am' is released on 19 November on SonyBMG