In her High School year book, Mariah Carey listed her 'likes' as "sleeping late, Corvettes and Italian guys". But that was back in the days of friendship bracelets and Farrah Fawcett flicks. "I still like sleeping late" she says. "And my idea of nice used to be a tacky late-80s Corvette, but I've evolved a bit since then. Now it's more like a vintage Mercedes. And my boyfriend [Luis Miguel, the singer known as the Mexican Elvis] is half-Italian, so I guess........" She guesses that essentially she's still the same girl that grew up on Long Island. Even though she is now the biggest selling female artist of the 1990s. And $250million better off.

Carey is sat behind a mixing desk in the hills of Capri. She is trying to put the finishing touches to Rainbow, the new album, but her French manicure keeps getting in the way. She is wearing cut-offs and sneakers - the practised look of America's sweetheart - and has a wholesome, healthy glow about her. Which is totally unfair. She is surviving on only one hour's sleep ("I'm still following my own time zone") and two bowls of breakfast cereal. "Cereal is my midnight feast. I know it's chocolate, and it's fattening. But the writing on the box is in Italian, so I don't understand the translation of fat grammes. Still, what I don't know won't hurt me."

When she gets up from the mixing desk, Carey is taller than I imagined. "Everyone says that" she says. "Everyone thinks I'm shorter. I'm actually 5" 9'." And I imagined her voice would be much higher. "Everyone says that" she says. "Maybe it's because I sometimes sing really 'aaah' [at this point, she sings a note somewhere up there on the whistle register] they think I'm going to talk like that. I have nodes on my vocal chords - that's why my voice is low. In New York, the pollution was killing me. LA was boiling my voice completely. But here, with the clear air and humidity, it's never been better."

The recording studio clings to the rocks, high above the Piazzetta - the little square on Capri known as Italy's sitting room. The date palms and carob trees are giving off a sweet smell now the sun has gone down. "That's something you can't get in New York" says Carey. But then she normally records above a girly bar on 48th Street. "I first came to Capri after that Pavarotti And Friends show in June [raising money for the children of Kosovo]. I needed to free my mind. I love water. It's a cleansing thing. I've recorded in Puerto Rico and in the Bahamas, but here the water is a turquoise blue like I've never seen before."

When your name comes from the song They Call The Wind Mariah, you are obliged to be a child of nature. Carey certainly doesn't disappoint - in her breaks from recording Rainbow, she swims in the grottoes off the island. "I found one where they say Mass once a year. I'm definitely bringing my mom out to see that. And my little brother - well, he isn't my little brother." Carey's only siblings, Alison and Morgan, are ten years her senior. Her 'little brother' is actually the son of Alison, an ex-prostitute and drug user. Carey took her mother's side in a battle over the boy's custody. And Alison, by way of revenge, is still threatening to write Carey's definitive tell-all biography.

Carey was the youngest child of a white mother (a mezzo soprano with the New York City opera) and a black father (an aeronautical engineer). They divorced when Carey was three. "The lack of a real closeness with my father has impacted upon a lot of the decisions I've made" she says. She doesn't really want to elaborate. She first demonstrated her extraordinary vocal talent when she was only two-and-a-half. She sang Rigoletto - in Italian - while her mother was practising at the piano. Carey's style is still recognisably operatic. The day after she graduated from High School, Carey headed for New York to make her living. She waited tables by day. And sang by night.

One night in 1988 changed her life. She met CBS Music president Tommy Mottola at a record industry party, and handed him a demo-tape. He listened to it on the way home, and offered her a contract immediately. He wanted $500,000 spent on her first video. He wanted $1,000,000 spent on her promotional budget. Carey was to become Mottola's project. And, as it happens, Mottola's wife. The pair had a fairy-tale wedding - after his divorce came through. But Mottola continued to act like her manager, and not her husband. He wanted to veto the photographers, directors and producers she worked with. The polite word would be 'protective'.

"I still don't think I've adjusted to the whole fame thing because I wasn't allowed to feel it for so long" says Carey. "I never went out, I was never in public. When I was in public I had to have the glasses and hat, you know. Living in a big mansion in upstate New York [with 14 baths and two pizza ovens], and being surrounded by only older people in the music industry, it started to make me feel like a recluse. Or someone weird. I could have friends around, but only in my house. I was never around everyday people. Now when people come up and ask for a picture, I'm 'Okay. You want an autograph? Fine'. It's much more normal to be in the mix with real people.

Carey likes to retire to her rooms (nothing too grand) and change before dinner. That means heels. Carey claims she runs faster in heels than she does in bare feet, but I doubt she's ever put it to the test - the limo is always just around the corner. She lights a candle, and flicks through her wardrobe. "A crochet top, I think" she says. It's her 30th birthday next year - and maybe time to start wearing serious dresses - but not just yet. "Arlette from Brazil - my assistant - can make me a top in a day. I like the fact they don't look shop bought." Carey has them in every colour, and every conceivable style. In her New York town house, she has to have them individually numbered.

Not many women can get away with crochet. But Carey can. "Last year I probably went up a size or two because for the first time in my life I took a vacation. Joan Rivers, at the Oscars, said 'Let me see Mariah. Everyone says you gained weight'. I was like 'You did not just say that to me on the freakin' red carpet at the Oscars'. You know what's really sick about that? The message we're sending to kids. Besides, I had a white dress on. And white makes you look bigger. I've lost weight since then but only because she sent me into a tizzy. When I was a little girl I was real thin. But muscular. I wasn't born to be a waif. She almost made me have a weight issue."

Carey isn't a vain woman. She insists that the days when she would only sit on the left-hand side of the limo (she preferred people to behold her from the right) are behind her. "I'm not vain" she says. "I'm insecure. Do you think vain people are vain because they're insecure? When I look in the mirror I just think 'Did my skin break out today - how am I doing?'" Her complexion is flawless. It comes from having your own electrolysis and facial equipment, and staying away from seafood. Seafood makes her break out. "I do have make-up on today" she says, "but when I walk around with no make-up, people usually tell me I look young." Or they get fired.

The relationship with Mottola ended in divorce in March 1998, after four years of marriage and nine months of separation. But Mottola remains her boss, which is why she's said to be in a rush to complete her contract. It puts her in a difficult position, and psychologists would have a field day analysing the video for Heartbreaker, her new single. It concludes with Carey actually beating herself up on screen. "It's just a bit of fun" she says. "I didn't want to look like I was taking myself too seriously. These days videos are out of control. All the posing. I just wanted to show another part of my personality."

The video is part of a campaign to rid Carey of the clean - if rather dull - image which has made her an easy target. Madonna (who implied she would rather be dead than Mariah Carey) and Sandra Bernhard (who made jibes about Carey's ethnicity) both took shots. "It makes me laugh" she says "because I grew up looking at these people like they were celebrities. I expected them to have more class. It's sad that Madonna has to make comments because she's an icon. No-one can touch what she's done. The fact that she had to make derogatory comments made her look petty. I found that kind of sad at this stage in her life. She should just be happy."

"But" - and her smooth face forms itself into wrinkles for the first time - "the whole Sandra Bernhard thing affected me more deeply. Mainly because it was a race thing. She was saying I was, yet again, same old same old, a white girl trying to be black. What I didn't like about it was the fact that she was using the word 'niggerish'. And she was allowed to get away with that. If someone was to say something derogatory about any one of the minority traits which she represents - and there are quite a few - everybody would be breathing down their neck in two seconds. But because it was about someone who is mixed, it was deemed alright."

Carey has come to accept she will always feels like an outsider. "Isolated, in a sense" she says. "From everybody. The people that can relate to me on one level, I don't know if they can relate on another. Someone who can relate to me as an artist - like another artist, who may have their own set of issues - may not be able to connect with my issues about feeling separate. Feeling like an outsider in terms of my race. I'm very ambiguous looking, and I've been through so much stuff that people who look more one way than another don't necessarily go through. People don't understand that unless they're really of mixed race themselves."

Acting makes Carey happy. Which is why she is currently working on All That Glitters, a Disney drama based on a multi-racial family; Double-0-Soul, an action comedy starring Chris Tucker; and The Bachelor, a romantic comedy starring Chris O'Donnell. "I used to love acting" she says. "But in the past thing [she never directly refers to what happened with Mottola], with the relationship, that wasn't acceptable. Now I'm acting again. In The Bachelor I have, literally, a 30-second cameo. I mean it's like 'Don't blink or you'll miss it'. It was a good experience, but a lot of the best stuff that I saw in the dailies wasn't used - it was, well, funnier."

Acting has become a substitute for therapy. "I remember once my drama coach said, 'Go to a place where you feel really safe'. I said, 'I can't think of one'. She said, 'Go to a place where you feel like no-one's going to mess with you.' I said, 'I don't have one'. She said, 'You can use your childhood'. That made me feel sad too. Well, finally, I've got my place. I was on this sailboat in Puerto Rico. I was with this really cool captain who had a toe missing, and there was this beautiful sunset. It was the first time I could ever do what I wanted and be myself. I finally felt a little bit of freedom. That's a good place to be."