Throughout the Seventies, David Bowie did not have fans. He had acolytes, disciples, obsessives; teens and 20s who would buy every record, watch every move, copy his clothes, his haircuts - the upswept flaming bush of Ziggy Stardust, the soul-boy quiff of Young Americans - his attitude.
Tony, a student friend of mine, idolised David Bowie. Back in the late Sixties, before the world at large even knew who Bowie was, Tony had even met him once or twice. Bowie was living in suburban Beckenham at the time - an aspirant pop singer, dabbling in mime, kabuki, the visual arts - running an arts project, and a couple of times Tony was invited back to Bowie's home to hang out, smoke a joint or two and talk.
This was before Bowie recorded The Man Who Sold The World, the album that made his reputation. The Man Who Sold The World was notable for two things: its cover, which showed Bowie lounging on a chaise lounger in a fetching silk dress, the first signal of the sexual ambiguity that would become his stock-in-trade; and its lyrics, which dealt explicitly with the thin line between sanity and madness, alluding to the history of schizophrenia in Bowie's family and suggesting, as the song had it, that Bowie, too, `would rather stay here with all the madmen/For I'm quite content they're all as sane as me'.
Tony loved the The Man Who Sold The World, perhaps because it not only mirrored the madness germinating in his own mind, but also legitimised it. Sometime in the early Seventies, Tony was diagnosed as schizophrenic and admitted to a mental hospital. I visited him there once or twice. On the door of his room he had a huge poster of Bowie in his incarnation as Aladdin Sane - the flash of lightning zigzagging across a face that looked like a death mask. I could imagine Tony in his room, tuning into the poster, picking up his own scrambled meanings and messages - A Lad Insane. The poster was calling him, and one day Tony walked down the long driveway of the mental hospital and took a bus to Beckenham, to see Bowie.
It was tricky, but eventually Tony found the house. There was no reply when he rang on the doorbell, so Tony opened the gate to the back garden, smashed the kitchen window and let himself into the house. After all, David would understand.
Tony looked around; the G-Plan furniture and swirly patterned carpets weren't as he remembered - but, hell, Bowie's taste was ever eccentric. Tony was sitting in the front room, in front of the electric log-fire, drinking tea, when the respectable suburban couple whose house it was eventually returned.
Tony was back on the ward within an hour.
Bowie had long since left Beckenham by then, of course, and probably long since forgotten Tony. It's difficult to place this correctly, but by the time Tony was smashing that kitchen window, Bowie was holed up in the Pierre Hotel in New York, a Rock Monster. He had rented two suites, at $700 a week, one for living in, the other transformed into a makeshift studio, where Bowie sequestered himself, making films of himself building scale models of the stage-set for his forthcoming nightmare-of-the-apocalypse Diamond Dogs tour.
`It's unbelievable,' says Bowie, leaning forward on the sofa in the New York recording studio where we are talking. `I'm a real hoarder, and I actually came across this film the other day, and it's so funny.
`John Lennon was around at that time, and every now and then the camera catches sight of him in the background, sitting there with his guitar playing hits of the day and saying, "what the bloody hell are you doing, Bowie? It's all so negative, your shit. All this Diamond Dogs mutant crap. Ha, ha, ha."
`I loved John. I remember asking him once what he thought of glam rock and he said' - Bowie adopts a plausible Liverpudlian accent - ` "It's just fooking rock and roll with lipstick." Which was very succinct, but not all that accurate. Ha, ha, ha.'
Bowie rocks back on his chair with laughter. He laughs readily. It's the first thing you notice. That and his immediate warmth. There is no hint of diffidence or reserve, no hint of mystery. Quite the opposite, in fact: the warm handshake, the south London mateyness, the air of breezy candour - all conspire to effect that great social trick of leading you to believe after five minutes acquaintanceship that you've known Bowie all your life.
This is unexpected because what we came to expect from Bowie in his heyday as a rock star was deliberate mystification. Better than anybody, Bowie understood the imperative of ambiguity and change in pop music - the fact that a moving target was harder to hit. In the Sixties `authenticity' had been the most highly prized commodity in rock music - a throwback to its roots in the `pure' form of the blues. Bowie's talent was for miscegenation, artfully appropriating avant-garde ideas and popularising them.
He also understood the power of sex in pop music. Mick Jagger flaunted effeminacy with the Rolling Stones; Bowie took it further, elevating the thrill of sexual ambiguity to a cri de coo-er! - `Oh you pretty things', he sang in one of his most popular songs, `Don't you know you're driving your mamas and papas insane.'
Above all, Bowie's performance was predicated on the deployment of disguise, shifting through a series of theatrical identities and musical styles which, as much as they enthralled his audience, begged the perpetual question: who exactly is David Bowie?
This was a game that made Bowie the most consistently inventive rock performer of his generation, and one of the most successful - until he ran out of steam sometime in the mid-Eighties, when his touch appeared to desert him, and nobody much seemed to care who Bowie was anymore.
So who exactly is David Bowie now? He is 50 next month. The father of a 25-year-old son, Joe, by his first marriage. Married for the past four years to Iman, the former fashion model, who now runs her own cosmetics company. They have a home in Switzerland, where Bowie has lived since 1981, although he is as likely to be found working and travelling in New York, London, Paris and the Far East. (He has a passion for Indonesia.)
You might describe him as all-purpose art-dilettante. He makes records; he acts (most recently playing Andy Warhol in the film Basquiat, directed by his friend, the painter Julian Schnabel); he collects paintings (German Expressionist and British contemporary) and paints himself; he designs wallpaper; he sits on the board of the art journal Modern Painters, for which he also writes art criticism. He has described himself as `a mid-art populist and postmodernist Buddhist surfing his way through the chaos of the late 20th century', which may explain why a lot of people nowadays think that David Bowie's worst vice is pretentiousness.
In fact, what he is most guilty of is being carried away on a tidal wave of his own enthusiasm. Talking of Bowie's work, Brian Eno, his sometime producer and close friend, describes him as `a wild intuitive, which is to say he works from his own excitement a great deal. He's capable of really fast, brilliant tangents off into somewhere that you hadn't suspected.' The same might be said of his conversation. Bowie talks in great, voluble torrents, darting from one topic to the next, parenthesising and then parenthesising the parathenseses, as if he has too many ideas for one conversation.
Mention the phrase `German Expressionism' (which Bowie does quite often) and it's the prelude to a protracted lecture about Pabst and Fritz Lang, the Blaue-Reiter enclave and how, as Bowie puts it, `the homemade quality of German Expressionist theatre generated an emotional flamboyance which contrasted with the slick professionalism of American theatrical design.' Want to talk performance art? Bowie will discourse at length on the artistic interest in bodily fluids, self-laceration, and the work of `the Viennese Castrationists', whose leader, Rudolf Schwartzkergler, he will tell you, `cut his balls off in performance, and died in an insane asylum'.
What about the occult? `Nobody professing a knowledge of the black arts,' says Bowie firmly, `should be taken seriously if they can't speak Latin or Greek. I know, I know,' he sighs, long inured, one suspects, to accusations of, at best, autodidactism; at worst, not allowing anybody else to get a word in edgeways. `If I've got a new rave about something I'll just talk endlessly about it and I'll explain where it comes from and how it started' If he had no artistic abilities of his own, he says, he would be `absolutely and perfectly satisfied to learn and teach'.
The afternoon has already provided something of a guided tour around Bowie's current enthusiasms. We have met downtown, at the studio of Tony Oursler, an artist friend of Bowie's, whose speciality is creating `installations' consisting of video portraits that are projected on to fabric dummies. A distorted image of Bowie gabbling to himself was running in one corner of the studio, while Bowie bounded around enthusiastically, elaborating on his plans to incorporate Oursler's `talking heads' into his forthcoming stage performance as surrogate backing singers.
Leaving Oursler's studio, we have made a pilgrimage, around the corner, to a particularly vivid piece of street graffiti that has sprung up overnight, Bowie striding along Houston Street, oblivious to the stares of passers-by - `Hey, that's David Bowie!' - a small crocodile behind him: me; his PR person; his personal assistant, Coco; his minder. We have now journeyed back uptown (Bowie in a black limousine, me following in a taxi) to the recording studio where he has been working on a new album.
He is pencil-thin, dressed in brown drainpipe trousers, a striped athletic top, and a baggy black corduroy jacket, decorated with three flying saucer brooches - a sort of space-cadet's pun on flying ducks. His hair has made some strange, atavistic journey back to the flame orange upswept brush cut he was wearing in the early Seventies, accentuating the paleness of his face, the finely chiselled features.
He settles back on to the sofa, lighting the third in an endless chain of Marlboro Lights. `There have been periods in my life,' he says, `when I have been so closeted in my own world that I would no longer relate to anybody. And I do love communication. These days more than ever I feel like a very social animal, which I wasn't at one time. And I love the freedom of it; I love the joy it brings. And I love the conflicts and the debates which go with being much more a fully active member of society.'
There is something disconcerting about this peroration. It is almost as if you are hearing someone talking about rejoining the human race. It is likely that more biographies have been written about Bowie than any other pop star of his generation. Two more have been published to mark his 50th birthday. He has never collaborated on any of them. His joke is that he plans to publish them all under one cover as the ultimate unauthorised biography. `Then if it were really successful, I could sue myself and make a fortune.' In lieu of this, Bowie helpfully offers a handy, back-of-the-envelope sketch of his own life. This suggests that there have been two occasions when he has lost himself: the first - `emotionally and spiritually' - in the Seventies, when he became mired in drug-sodden isolation; the second, `artistically' in the Eighties, ironically, at the time of his greatest commercial success, when he ran out of creative steam.
The supposition underlying this thumbnail thesis is that Bowie has now found himself again, whoever `himself' might happen to be. Bowie has always had stories to tell about himself - not always truthful. In the Seventies, for example, he was fond of likening his early childhood in Brixton to the rites of passage experienced by young bloods on the mean and picaresque streets of Harlem; the truth was that by the time he was six his family had moved to the tree-lined, net-curtain twitching streets of suburban Bromley, and that his early teenage years were stultifyingly uneventful. The slightly eerie difference between his left and right eyes - the left pupil is so dilated that it resembles a tie-dye T-shirt - was variously attributed to alien origins, schizophrenia or molecular reconstruction through drugs: the prosaic truth is that he was once jabbed in the eye in a school playground argument over a girl.
These fibs are merely the usual tricks of the pop trade, of course, but Bowie's propensity for self-mythology went further, creating a series of alter-egos which enabled him to make a career out of an identity crisis. `I think my problem used to be that I was always shy and fairly awkward in social situations,' he says. `All through my youth, I would use bravado and device - costume and flamboyant behaviour - in a desperate attempt to not be iced out of everything.'
In other words, so you didn't have to be you?
`Exactly.' Bowie stubs out his cigarette, and reaches for another. `It's interesting how you can do this at parties. In a simple family game such as charades; you see these incredible manifestations of personality come out of Uncle Bill or whoever when he's describing something in mime. That device allows you in an exaggerated form to display who you are. And I used a lot of those things.'
His first public charade, the androgynous and unearthly Ziggy Stardust, was, in a sense, an artist's caricature of a rock star: glittering, outlandish, larger than life. It became a self-fulfilling prophecy. `Very much so,' he leans forward, warming to the theme. `And I think I encouraged that. Having created this character, to then want to become him was incredibly tempting. And I was the first volunteer.'
In some strange process of metamorphosis, Ziggy was taken over by the glam-rock icon Aladdin Sane, then the desiccated Thin White Duke, then the `white soul boy' of Young Americans, until the creator had lost sight of himself in the creations. `It's OK,' says Bowie, `as long as you're really in control of the image, as a painter is, for instance. But when you're using yourself as the image it's never quite as simple as that. Because aspects of your own life get mixed into the image that you're trying to project as a character, so it becomes a hybrid of reality and fantasy. And that is an extraordinary situation. Then the awareness that that's not the real you, and you're uncomfortable having to pretend that it is, makes you withdraw. And I withdrew, obviously through the use of drugs, as well, which didn't help at all.'
This sense of confusion reached its nadir in the mid-Seventies - what Bowie describes as `my first period of isolation' - when he was living in Los Angeles, leading a shadowy and largely solitary existence, enveloped in a cocoon of cocaine and messianic self-importance. A confusing period, he reflects. `I felt like I was involved in this insane one-man voyage that was just pulling me along.'
The occult had made its way to the top of his reading list - the album Station to Station, that he recorded in 1976, was, he now says, a step-by-step interpretation of the Cabbala, `although absolutely no one else realised that at the time, of course' - which led, in turn, to `Grail mythology' and then to an unhealthy interest in the role of black magic in the rise of Nazism. `Being seriously involved in the negative,' as he puts it.
This was the period when he was quoted as saying that `Britain could benefit from a fascist leader', and apparently declaring himself as a prospective candidate. In the end, the clouds of delusion and the clouds of cocaine were all too much. `I blew my nose one day in California,' he once, memorably, recalled, `and half my brains came out.'
He decamped to Berlin, where, on one occasion, he was seen in a cafe with his head in a plate crying `Please help me'. `I was in a serious decline, emotionally and socially,' he now says. `I think I was very much on course to be just another rock casualty - in fact, I'm quite certain I wouldn't have survived the Seventies if I'd carried on doing what I was doing. But I was lucky enough to know somewhere within me that I really was killing myself, and I had to do something drastic to pull myself out of that. I had to stop, which I did.'
There is nothing particularly novel in this. The idea that the path of excess leads to wisdom was, of course, a required text for the Sixties. Reading Jack Kerouac's On The Road at the age of 15 was, Bowie says, an epiphanous moment. (`The only people for me are the mad ones, the ones who are mad to live, mad to talk, mad to be saved, desirous of everything at the same time, the ones who never yawn or say a commonplace thing, but burn, burn, burn like fabulous yellow roman candles')
There is a time in any teenager's life, I suggest, when, consciously or not, they make the choice between staying on the rails and going off them. `Oh yes, and I chose the second course, definitely. I think I fundamentally opted out of a controlled environment - the workaday kind of life that I found repellent, that I just couldn't take seriously. I don't think I ever felt that life was very long. It was certainly no surprise to me that I got old. I don't know if that's a good or a bad thing, but I was always terribly aware of its finiteness, and I always believed that if we only have this one life, then let's experiment with it.
`We know what can happen - you can get a job, go to work, you can follow that line of perceived security. But I think there's a different kind of security, which is trusting to and living by a code, of almost drifting where the wind takes you. And I spent well into my 20s doing that - just throwing myself wholeheartedly into life at every avenue and seeing what happened. Taking drugs; being totally and completely and irresponsibly promiscuous' He pauses, chuckling to himself. `To the best of my abilities. Just getting into situations, and then trying to extricate myself from them as they occurred.'
Sexual experimentation was a part of that. His public `coming out' to Melody Maker as a bisexual in 1974 suggested either a bracing honesty, or a shrewd understanding of the shifting sexual barriers of the time - it was probably a bit of both. In any event, it was a cause du scandale which would hardly raise an eyebrow today.
His first wife, Angie - the rock wife from hell - an American model whom he married in 1969 and divorced (acrimoniously) seven years later, wrote her own book which gleefully recounted details of Bowie's orgiastic excesses and as much sensationalist claptrap as she could muster. She recently appeared on television accusing him of hypocrisy for having eventually declared himself resolutely heterosexual.
The truth is, Bowie suggests, that his bisexuality was merely a phase. `I was virtually trying anything. I really had a hunger to experience everything that life had to offer, from the opium den to whatever. And I think I have done just about everything that it's possible to do - except really danger-ous things, like being an explorer. But anything that Western culture has to offer - I've put myself through most of it.'
The conclusion that he eventually came to, he says, was that he is `not a particularly hedonistic person - I tried my best. I was up there with the best of them. I pushed myself into areas just for experiment and bravado, to see what would happen. But, in the final analysis, it's not really me.' What he now recognises, he says, is that the peregrinations through drugs, hedonism, experience - the road of excess - were all part of `trying to recognise what the spiritual life is within myself, and how to identify it'. He pauses, mindful that he is broaching an area that some people would regard as `awfully hippie trippy'.
As a teenager he was drawn to Buddhism. For a year he studied under a Tibetan lama and says that at one time he contemplated becoming a monk, `until my teacher told me I wasn't born to be one. But so much of what first appealed to me about Buddhism has stayed with me. The idea of transience, and that there is nothing to hold on to pragmatically; that we do at some point or another have to let go of that which we consider most dear to us, because it's a very short life.
`The lesson that I've probably learnt more than anything else is that my fulfillment comes from that kind of spiritual investigation. And that doesn't mean I want to find a religion to latch on to. It means trying to find the inner-life of the things that interest me - whether it's how a painting works, or exactly why I enjoy going for a sail on a lake - even though I can't swim more than 15 strokes.'
I wondered if he had encouraged, or discouraged, his son from following the same path. Having survived the setbacks of a broken home, education at Gordonstoun and being christened `Zowie', he had the good sense to change his name to Joe and is now studying for a doctorate in philosophy at Vanderbilt University in New York?
`Whether it was me encouraging Joe to be curious about life, or whether it was just a genetic thing, I don't know.' He made a point, he says, never to brow-beat him about anything: drugs, sexuality, his choice of career. `The only times when I've lapsed into strictness' the word lapsed seems significant - `is in the matter of fundamental morality, that it's wrong to harm or to steal, the requirement for honesty. I do think I'm basically an honest person and I know that he is a very honest person.'
Bowie took custody of Joe after the break-up of his marriage in 1976, when Joe was five. `He's seen me through some of the most awful depressing times when I was really in absolute, abject agony over my emotional state; the heights of my drinking or drug-taking. He's seen the lot. So he's had the full dose of me - more than he'll ever need again.'
Predictably, perhaps, the son could not be more different than the father. Joe doesn't smoke or drink; he has been in a stable relationship with his girlfriend for the past five years; he is a keen rugby and American football player. `I look at him sometimes and I'm amazed we're related. But we have just the most wonderful relationship.'
The journey from the playing fields of immoderate excess to the tempering pastures of sober middle-age - via the public confessional to recant on the sins of the past - might amount to a text-book lesson on Bowie's generation, and for many of his contemporaries. `I guess that's probably known as maturity,' says Bowie with a laugh. `I just matured late.'
His marriage to Iman, he says, came at a point when he realised for the first time that `I was actually beginning to find my life really pleasurable, and I just wanted to share it with someone else. And one person was all I wanted.'
For a while he was in a relationship with a dancer named Melissa Hurley, more than 20 years his junior, but the age difference, he says, was too great. `I recognised that it could only bring trouble in the future. So I let go of that. Then when I met Iman it was just so instantaneous. It was really one of those overnight things. In fact, it was so overnight we knew we should wait a couple of years before we got married, to make sure we weren't kidding ourselves. And fortunately we weren't. It's just been such a joy.'
They married in Florence in 1992 in the modern style, attended by just a few close friends and a team from Hello! magazine. `You couldn't tell what was sincere and what was theatre,' Brian Eno remembers. `It was very touching.' Eno credits marriage with having transformed Bowie. `Since he's got married he's been very up. And a real pleasure to be with from that point of view.' Eno first started working with Bowie in his recuperative period in Berlin in 1976, producing a trilogy of albums in that period - Low, Heroes and Lodger - and last year's album Outside.
`The condition David was in in the late Seventies, you'd probably describe as slightly manic-depressive,' he says. `I mean, I don't think he had a recognisable condition or anything, but he was unpredictable mood-wise and he could become very depressed. He was pretty up and down. Now, most of the time, he's pretty up.' It is as if, says Eno, Bowie has `sorted out the bottom half of the curve'.
Bowie wants to play me some of the tracks from his forthcoming album, Earthling - a title that plays none too subtly to Bowie's new persona as an ordinary, affable, if somewhat arty, bloke. In the studio an engineer cranks out the songs at full volume. It is always a potentially awkward moment, listening to a performer's work when he is sitting beside you - how do you compose your face into a rictus of approval if the songs are awful? In fact, they sound like the strongest he has recorded in years: densely textured - `industrial rock', says Bowie - yet rich with the sort of commercial hooks that have been absent from his more recent work. Bowie was always clever at appropriating musical styles and stamping them with his own signature - the `white boy' soul music of Young Americans; the ambient electronic atmospheres of Low. Earlier in the year he played some festival dates with the new generation of techno groups such as the Prodigy and the Chemical Brothers - the paterfamilias among the young pretenders - and he has artfully incorporated the new trend of drum 'n' bass into some of his new songs.
Bowie's biggest-selling album, Let's Dance, was recorded 13 years ago, and, as is so often the case, success brought problems. The conventional wisdom about Bowie's recording career is that up until then he had always been one step ahead of the mass market. Let's Dance, which sold six million copies around the world, was where the mass market finally caught up. And ever since then, Bowie has been one step behind.
Bowie acknowledges that the mid-Eighties was the lowest point in his career. With the success of Let's Dance, he says, he suddenly found himself performing to what he describes as `a Phil Collins kind of audience' and, for the first time in his career, he started to tailor his work to what he imagined his audience wanted to hear, rather than what he wanted to play. `Basically, I got myself into a terrible mess.' What saved him, he says, was meeting the American guitarist Reeves Gabrels.
`Reeves could see that I was compromising to try to get mass acceptance, and it just wasn't working. And he said to me, why are you doing what you're doing when it so obviously makes you unhappy. Do what makes you happy.' With Gabrels, Bowie formed the group Tin Machine, deliberately submerging his identity in an attempt to be just `one of the boys'. It was, he now admits, `a disaster touched with glory. A glorious disaster'. Critics were hostile, audiences bemused. Record sales negligible. `But for better or worse it helped me to pin down what I did and didn't enjoy about being an artist. It helped me, I feel, to recover as an artist. And I do feel that for the past few years I've been absolutely in charge of my artistic path again. I'm working to my own criteria. I'm not doing anything I would feel ashamed of in the future, or that I would look back on and say my heart wasn't in that.'
It is not commercial success that now concerns him, he says, so much as `feeling that I'm still somewhere in the dialogue' - not only in the field of pop music, but wherever his interests happen to take him.
`I do feel that there is a much more inclusive feeling among the arts communities in general - music, literature, the visual arts. And I'm determined that if I want to paint, do installations or design costumes, I'll do it. If I want to write about something, I'll write about it.' He has recently discovered the pleasures of collaboration - `action' paintings with Damien Hirst, installations with Oursler and a continuing series of Outside albums planned with Brian Eno. This will lead to a stage production for the Salzburg Festival in the year 2000, to be produced by Robert Wilson.
He was always a work obsessive, he says - `I don't like wasting time.' But nowadays he is careful to make sure it doesn't affect his relationships. `I have dinner with friends; I remember to phone them up!' His tone of voice suggests a novel pleasure in the commonplace rituals of friendship.
`I think the internal and exterior values in my life have kind of leap-frogged over each other into a more positive area,' says Bowie - which, I think, is his characteristically roundabout way of saying that he feels particularly good about life.
`Being as much of a chameleon as David has been is, at the least, unconventional,' says his friend Brian Eno. `The worst thing for anybody is to not have a clear sense of yourself and be terribly worried about it. But I think he's come around to the idea that you can either think you have a very clear sense of yourself, or not worry about the fact that you don't. Now he thinks, who cares?' `It's true,' says Bowie. `I really do feel an overwhelming thankfulness that I can get out of bed every day; that I still have all my faculties, and that nowadays my appetites seem to be sane ones. That's enough.' He falls back on to the sofa with a laugh. `Sometimes I'm so happy I depress people.'