CELEBS SUNDAY (BY ALEX CANFOR-DURMAS)

The singer with the biggest voice of them all on finding love again, ugly-ing up for her art, stepping into Helen Mirren's shoes, and that Diva tag.

It's 8:30pm on a humid autumn evening in New York and the traffic's ground to a halt. The gridlock is worse than usual – apparently President Obama is in town.

So it's ironic, but I think I'm going to be late for my interview with Mariah Carey, a woman who has a reputation for being rather late herself.

Yes, Mariah is known as the Head Girl of prima donnas – and then some. Even now, as I sit impatiently in my yellow cab, Mariah Carey could be making outrageous demands: the cushions should match her nail varnish; the temperature of her iced tea should be monitored. And what's that, glinting on the table? It's a goldfish, wearing a lilac tiara, just like the singer's own.


That's the sort of thing I'm expecting. I'd read the stories, but could they really be true?

'What say you we speed things up?' the can driver suggests, springing into action with a sharp right turn. I lurch across the seat, but it looks like I'm not going to be late after all. I'll arrive with a bruised shoulder – but I'll be on time.

And so is Mariah Carey. That's my first surprise. In fact, she's been at the hotel most of the day giving interviews to promote her sultry new album, Memoirs Of An Imperfect Angel.

The second surprise is how relaxed everyone around her appears to be. There's none of the edgy nervousness that vibrates around a room when a difficult star is present – everyone seems calm and good-humoured. I'm informed Mariah will be available in five minutes, as she needs to record a TV message for a programme celebrating her friend Simon Cowell's birthday.

On cue, the door opens, and Mariah Carey gallops into the room. Tall as a supermodel (5ft 9) she's all legs and hair, with the latter cascading in tawny curls over her shoulders. Dressed in black, she looks like she's been poured into her tight trousers, and her shirt is unbuttoned just enough to reveal a substantial cleavage and an elegant necklace that spells out 'Angel.' The look is simple, but effortlessly glamorous. Reclining on a sofa, the singer waits patiently for her make-up to be retouched, then, looking into the camera, she starts to sing Happy Birthday to Simon. [The video was shown at his birthday last month.]

She stops abruptly. 'I can't sing!' she exclaims. 'I've been talking for 50 hours today and my voice won't be good enough for Simon!' Suddenly she's more like a nervous X Factor wannabe than what she really is: the biggest-selling female artist of all time (200 million records worldwide and counting) and – let's not forget – the possessor of an extraordinary vocal range. Even so, Mariah decides to speak to camera instead, in her seductive Long Island drawl. If that doesn't make the music mogul sit up, nothing will.

Later, when everyone's left the room, I speak to Mariah, 39, alone. There's no agitated publicist sitting in the corner censoring every question. It's just me and Mariah, who has her legs curled up under a rug. 'I hope you don't mind, but this is cosier,' explains the singer.

Memoirs Of An Imperfect Angel is her twelfth studio album, and it has the sexy, loved-up feel of a woman fulfilled. Its themes are love, ar all its stages. Eighteen months into a happy second marriage, was it healing for Mariah to look back at her own journey of the heart? 'Yes, because I was able to build humour into some of the lyrics,' she discloses, 'and that helped. I've spent so much of my life feeling like I had to be a "good girl" when it came to guys. I had to be careful who I got involved with in case they bragged, but when you finally find the right person, you don't feel angry you went through some unhappy experiences. It all suddenly makes sense.'

The 'right person' in this case is actor, rapper, TV host, millionaire and current presenter of America's Got Talent, Nick Cannon. They announced their marriage after a whirlwind, two-month courtship in April last year. One track on her album, The Impossible, is dedicated to Nick. 'You rescued my love/You did the impossible/See, I had almost given up,' she sings. So what makes him different from all the other guys? 'He's giving and loving,' she smiles. 'He's also witty and fun. We have a good time together, like big kids. I adore him. He's a special person in every way. It can be a little tough, having a relationship when you're under such public scrutiny. But I like it better than being alone.' And the sexiest thing about him? Mariah hesitates, looking politely shocked. 'That's sort of private,' she says coyly, glancing down. 'OK, he's great-looking with a good six-pack.'

Mariah's in pretty good shape herself. What's her secret? 'I have to be careful with my diet,' she admits. 'Fortunately I"m quite muscular, so I can lose fat quickly when I try. At the moment I'm on this bleak pak choi diet. Ugh! I can hardly stand it, but I'm trying to lose a few pounds. I try and work out from where these few pounds need removing.' Her ankles, perhaps? Diet aside, Mariah Carey seems happy. Fulfilled in her personal life and with a stellar 20-year music career to look back on, she's now also experiencing an about-turn in her acting ambitions. In her most recent film, Precious, she is almost unrecognisable in the small, but hard-hitting part of a social worker. The role earned her a 15-minute standing ovation at the Cannes Film Festival this spring, and there's even speculation she could grab the Oscar nomination for Best Supporting Actress. She's come a long way since being panned for her 2001 performance in the film Glitter, so it must be quite satisfying. 'Well I've been doing independent films people don't know about and learning my trade that way,' she reveals. 'Someone told me Helen Mirren had been offered the role of the social worker, but had to pull out. So it was daunting to try and fill the shoes of this great Academy Award-winning actress. But then I decided to snap myself out of that mind-set and figure out what I could bring to the role.'

Almost as daunting for Mariah – a woman whose name is synonymous with glamour – was the make-under she had for the part. It left her unrecognisable, even to friends. 'It was hideous!' she screams, in mock horror. 'I had dark circles added under my eyes, a moustache. The hair was disgusting, the clothes horrible. But I'm willing to do anything for a role, to make it authentic. I'm proud of that part, and I want to do more films – especially independent ones. I'd love to work with Woody Allen.'

Mariah is glad, too, that she is at last receiving recognition for her song-writing and producing skills, even though she's been doing both since her teens. She co-wrote and co-produced all the songs (bar one) on her latest album. In fact it was Simon Cowell, who pointed out to last year's X Factor audience that Mariah's song-writing abilities were rarely given due credit.

'That was very nice of Simon,' concedes the star, who was mentoring the contestants during Mariah Carey Week. 'The problem is, unless you're behind a piano or a guitar, you're looked on as a diva.' Ah, the 'd' word. 'Diva' has practically become Mariah Carey's middle name. But what's behind this reputation, and how does she feel about it? Philosophical, it would seem. 'At its heart, I think it's lazy journalism,' she offers. 'I was on the first Divas Live show (in the States) and that seemed to kick the whole thing off. You know, my mother – who was an opera singer – used to use the term as a compliment: it meant a very talented singer. But I looked it up in the dictionary recently and now it also means a difficult and demanding woman. I guess people like to put you in a little box, and that box fits me because I have the big hair, and I wear the tight dresses on stage. But that doesn't mean I'm difficult or nasty,' she says earnestly. 'I remember a story in the British press, saying I'd demanded rose petals be scattered on the carpet of a London hotel when I arrived. The truth is, we'd just landed, it was 3am and all I wanted to do was go straight to my room. The back entrance would have been fine, never mind rose petals! I'd never ask for anything like that. But that sort of stuff is written about me, so I've just learnt to shake it off.'

In fact, Mariah still has the same friends since her school days, and a management team who've lasted 15 years. Hardly the track record of a diva. 'I think one of the most down-to-earth things about me is that I value my friendships,' she says simply. 'My friends know MC keeps her word. I'm very loyal and never divulge their secrets.'

Then my time's up. 'It was nice to meet you,' says the singer, uncurling herself and hugging me warmly. Diva? All I found was a sweet woman. And her voice isn't bad, either...

The single, I Want To Know What Love Is is out 14 November. The album Memoirs of An Imperfect Angel is out 16 November. Precious is released in the UK in February 2010.