Marianne Faithfull: I was saved by sex

The prototypical Sixties rock chick shares her secrets with John Walsh

The first thing Marianne Faithfull says to me is, "I'm having a pee. That is allowed, isn't it?" I am not in fact in the lavabo with her – there's a solid door between me and her disembodied voice. I'm standing in her hotel room regarding the vast bed that takes up most of the space. The bed is a complicated crimson brocade object hung with complicated drapes; it instantly makes you think "boudoir". It's a word you tend to associate with the lady who you're about to meet.

Then she appears from the bathroom. The prototypical Sixties rock chick is surprisingly small, designer-clad (Luella Bartley jacket, Balenciaga trousers, Chanel pumps) and smiling fit to burst. A wall of maquillage and mascara make her actual features hard to discern, but you notice the wide Joker mouth from which emerges the most astonishingly cracked voice. It's the voice of Ursula the Sea Witch in The Little Mermaid, the grotesque shape-changer who longs to steal Ariel's mellifluous young vocal cords...

Her publicist presses into her hand a package that's arrived at the hotel. It's a portrait of her by Mario Testino, taken last year at her house in Dublin – a little gift from the world's trendiest photographer. Dear Mario. She is very pleased, in the way Queen Elizabeth I would be pleased to receive a tribute in emeralds from a far-off courtier. She waves me to a chair and extracts a Marlboro Light, the first of five or six in the next hour. I produce a chrome lighter in the shape of a headless female body. "Oh, you boys," she says, with fake exasperation. "That's all you really want, isn't it? Just the body and no head..."

She goes off into the first of a hundred wheezingly infectious bursts of laughter. And you think – exactly one minute ago, she was a queen, gracious but aloof. Now she could be behind the bar of the Rose and Crown. Ms Faithfull is full of contradictions and surprises. The first surprise is what good company she is. I was apprehensive of meeting her, what with her reputation as a dragon of tardiness, off-handedness and fuming hauteur. None of these is on display. Instead, she is friendly, forthcoming and talks about her friend Anita Pallenberg, former girlfriend of Keith Richards and Brian Jones – and, indeed, of Faithfull herself, who famously also went to bed with both of them, as well as with Mick Jagger, her most heartbreaking squeeze.

Anita is staying at the same hotel. They go to fashion shows together. Last night they were at the Yves St Laurent farewell extravaganza. But (I say), the Brit awards were on the same evening; shouldn't she have been there instead? "The Brits? Why would I be there? I go to the Brits when I've won something," she says crushingly, as if that happened all the time. No, fashion is her thing at the moment. Her new best friend is Kate Moss; they're always being photographed together. She's fond of Sophie Dahl, who has been courting Mick, whom she still sees ("but we move in very different circles"). She and Anita don't like staying out late. They swanned home to the hotel early last night. "We go into subjects together, you know," says Marianne. "Our subject at the moment is the French Revolution. It started when I saw my friend Roger Waters [the ex-bassist of Pink Floyd] who is writing an opera called Ca Ira. He was reading a biography of Marie Antoinette by Antonia Fraser. I got a copy on the net, and it's just amazing, it's like a thriller even though you know what's going to happen. Then Anita saw me reading it, and she read it in one day. And now we've done our Marie Antoinette bit, we're onto the French Revolution."

It's quite easy to think of both ladies as rock aristocracy. There's a touch of the Duchess in Alice in Wonderland about both of them, to go with their Austro-Germanic roots. "Anita doesn't think much of the Hapsburgs," says Marianne, lighting up again. "She thinks they're dreadful".

She is busy promoting her new album, Kissin Time, out on Monday, and is keen to discuss her collaborators. The 10 new songs vary wildly in quality, from a couple of stony dirges written with Beck Hansen to a brace of fine anthemic tunes co-written with Billy Corgan of the Smashing Pumpkins. The most intriguing cut, however, is "Sliding Through Life on Charm", in which Pulp play a remixed "Common People" to a startling autobiographical lyric: "Suburban shits who want some class/ All queue up to kiss my ass/ And I was only trying to please./ I never got any royalties." What's really striking, though, is that the words were written by Jarvis Cocker.

"He came to one of my gigs; Chrissie Hynde introduced us, and that was that. One night we were both on TFI Friday and I said: 'Jarvis, there's a song I've been trying to write for 20 years but I've only got the title. Could you write it for me?' Three years later, I got this demo tape in the post, with the lyrics written on the back of the envelope. He wrote it in my voice and said all these things I would have said if I'd had the courage, if it hadn't been beaten out of me in the Sixties." Indeed, like "I wonder why the schools don't teach anything useful these days/ like how to fall from grace/ and slide with elegance from a pedestal I never asked to be on in the first place".

But you've written plenty of songs, I say. What stopped you writing this one? "I had this conventional education. I thought you had to rhyme all the time. 'Sliding Through Life on Charm' rhymes with... there's only 'arm', 'farm', 'alarm', 'calm', 'ma'am', 'charm'. Well, you're fucked really. You can't write a you can't write a rock'n'roll song with those words, can you?"

Isn't she priceless? Ms Faithfull is, by turns, naïve and knowing, regal and tarty, outraged by bad behaviour and cacklingly indulgent about it. She is capricious in a way only spoilt princesses in fairy tales are meant to be. She's clearly proud of her reputation as the ultimate rock horizontale (who else could number Jimi Hendrix, Gene Pitney, most of the Stones, Allen Clarke of the Hollies, Chris Blackwell, and David and Angie Bowie among their conquests?) but comes over all hoity-toity about the impertinent way people ask her for details.

"No English journalist would ask me things like I have been asked by German and Dutch journalists." For example? "This German guy leans over and says, 'Zo, Miss Facefull, vood you pleeze tell me, vot is the size of Mick Jagger's penis?' I was gob-smacked. I couldn't speak for 15 minutes. I got home and cried and cried."

But surely she was used to being asked such things? She regards me regally, Queen Victoria this time, inspecting a raggedy junior footman. "I just don't understand," she says with awful slowness, "why anyone would think that I'm the sort of woman who would ever say anything in reply". Heavens, no. The very idea.

Since her name is synonymous with sex, drugs and rock'n'roll, which of the first two had she preferred? "I'll tell you this," she says with deliberation. "This will keep you off drugs. When you start taking drugs, you stop having sex. It kills your sex drive – women get to feel they don't need sex. It's obvious, if you think about all the imagery of injecting. Heroin did its job for me; I was in a lot of pain, it stopped me killing myself. But then I started to miss sex. So you could say my life was saved by sex."

Marianne's epic swan-dive into the lowest swamps is well-documented, as is her glamorous background. She stills talks with animation about both, as if they're scenes from a favourite film she's seen a hundred times. If (as her new CD suggests) the world is full of 17-year-olds called Eunice dying to throw their lives away in emulation of her, who was her own Marianne back in 1964 when she became London's favourite Convent Girl Gone Bad?

"My wicked mother," she says. "She was wonderful, dangerous and exotic, Austro-Hungarian-Jewish. Nobody in Reading had a mother like that." Her father was a former spy, "about as barkingly eccentric an Englishman as you could meet. He translated Michelangelo's sonnets. His great subjects were Boccaccio and Dante. He was a philologist, and read Italian and Renaissance Studies at Bedford College, London. They were extraordinary and I was very lucky."

So what was she rebelling against? "My mother sent me to a convent school," she replies. "Because I was so clever, they offered me a free education, as long as I stayed until I was 18, went to university and became a Catholic. And I did. And I felt somewhat used after that." She met Mick and Keith and Andrew Loog Oldham, the Stones' manager, at the first party she attended in London, at the age of 17. They formed an instant rapport, although she was then going out with the man who became her first husband, John Barton, the father of her son Nicholas.

Had she thought at the time, "This is rock'n'roll. I can do anything I want now?" "No," says Marianne. "I didn't even know I was pretty." Come again? "Oh, I knew I was nice-looking, but I didn't know I was that pretty. I didn't realise until I watched Hamlet in the 1970s [she played Ophelia to Nicol Williamson's prince]. I burst into tears when I saw myself. I thought, 'Blimey – that's what I look like'."

There it is again, that strange sense of a woman watching her own life at one remove, unable to connect what's inside her to what people have made her. She dramatises her hard times in the same way. "I had a lot of hard times, which I laid on myself. Why? I think I was trying to be a Great Artist. [She laughs with bitter sarcasm.] "And also I needed some privacy. To live on a wall in Soho, with no address and no phone number, it was the perfect antidote to the Sixties. I just disappeared. I'd given up. I was gonna die. Nobody could find me. Francis Bacon would turn up sometimes and drag me off for a good meal."

Now she's back in music, what did she think of her voice these days? Nothing indicates Ms Faithfull's unsinkable non-self-awareness more than her conviction that she sounds a bit like she used to. "What we wanted to do on Kissin Time was, we all had the feeling that that little pop voice hadn't really gone away, and we wanted to bring it back." Whaaat? You mean, the little pop voice on "As Tears Go By"?

Marianne, I say, you know the Three Tenors? You and Tom Waits and Leonard Cohen could be the Three Baritones. "No, I don't mean it's like that," she says with asperity. "But there's a charm that hadn't been there for a long time, and it's really there. Obviously, it took a long time to get rid of all that anger and fury, which had to go somewhere". And now they've gone?

"I'm much happier now. I've been in love for a long time. But I've also got two fantastic grandchildren, and a son I'm very proud of, and a rather decent daughter-in-law. I like my friends, I like living in Dublin. I'm much happier". She reflects for a minute. "Though I would like a little more dosh, actually." And she laughs like a collapsing piano accordion. Marianne the barmaid and Marianne the spoilt queen make a striking combination. What shall we call it? Marianntoinette?