If glam is being revived primarily as a fad or a marketing tool, its reappearance comes nonetheless at an opportune moment: a time when pop needs fresh inspiration in order to recover from five years of lumpen lad culture, when it would benefit hugely from an injection of sexual and sartorial ambiguity. The world may be a more benign place for a sexually confused teenager than it was 25 years ago, but the masculinist stereotypes of babe-worship seem, if anything, more prevalent than they did in 1973.
"I think the main application of glam now, and why it's worth getting excited about it again, is that we need something to roll back the tide of lad and bloke culture," says perennial pop sage Jon Savage. "I can't believe how conservative everything's become. I mean, if The Sweet were on Top of the Pops now, you'd probably have front-page headlines and outrage."
Observing these cultural fluctuations with especial interest is the generation of fans who came of age with glam, who lived it the first time around, and who will doubtless be checking out Velvet Goldmine to see how it tallies with their own memories of mascara and Marc Bolan.
"I know people who grew up in the Sixties say they were free, but in a way I think we had a bit more freedom," says Hampstead mother-of-three Esther Rinkoff, 42. "Everything was much more accessible. Our parents really didn't give a shit about what we were doing: we came and went as we pleased. I've got an 18-year-old son now, but just through growing up in that period I feel I can relate to music today. I'm not saying, `Turn that rubbish down.' A lot of the stuff my son plays today is very reminiscent of Bowie and that era."
For Rinkoff, as for so many others, glam rock was the first teenage music which genuinely felt like it was "hers". Too young to fully appreciate the Beatles and the Stones, she became a true pop consumer only with the advent of Bowie, Bolan and Roxy Music.
"We didn't think we were teenyboppers," she says. "We felt we were really hip. Bowie to us was much more intellectual than The Sweet. I must have worn out Hunky Dory - my friends and I used to listen to that over and over again. And then we all saw the Ziggy show. It was a blissful time. We were all very chilled-out, very brought together by the music. We'd bunk off school to queue up for tickets. We'd spend every Saturday at Biba and Kensington Market, and we'd go to Shelly's and buy our outrageous platform shoes and boots."
Rinkoff says that part of the attraction of glam was the femininity of the boys who were into it. "The boys really showed their feminine side," she says. "One of my male friends was really pretty, and he wasn't ashamed to show that he could be a bit feminine. I certainly geared towards those kinds of boys, boys who related to Bowie and Marc Bolan. I think most of them were just playing with the gay thing. I couldn't say for sure, because I lost touch with them."
All over Britain, in public schools and comprehensives alike, boys were seduced by glam's androgyny and excess.
"When I got hooked on glam, it happened in an instant," says Old Harrovian and therapist Christopher Edwards, 44.
"I was watching The Old Grey Whistle Test, and the camera closed in on these calf-length, lace-up, green day-glo boots, progressed up to this sort of Chinese quilted jumpsuit, and then you heard the opening three chords of "Queen Bitch". And it was Bowie, and it was instant love - I was gone. A couple of months later I found a photo of him in the NME, and I took it down to this little barber's in Wealdstone and said, `Cut my hair like this.' And they said, `No way - that's a girl!'"
For Edwards, glam was, if nothing else, an antidote to the odious Mark Thatcher, who was in his form at Harrow. "Glam was the antithesis of the rugger-bugger image," he says. "We used to be as camp as we possibly could. Suddenly being bisexual was cool among my friends. It was the rebellion we'd been looking for." A 1972 Roxy Music show in Manchester remains, Edwards says, "the best gig I've ever been to ... so completely out there, so sexy and stylish".
Glam provided just as much of an anti-rugger-bugger stance for writer Dave Rimmer, 43, who grew up in Newcastle and numbered future Pet Shop Boy Neil Tennant among his mates.
"There was a level at which being into glam was a big f***-off to all the twats who used to beat me up," he says. "My friends and I all took great delight in dyeing our hair orange and wearing make-up, just because it was two fingers to all the rugby players, who couldn't understand it at all. We'd parade around making the most of what naive sexual ambiguity we could muster. And it actually meant that people were a bit scared of us for a change. There was a certain power in it - the power of belonging, but also the power of freaking people out: `epater les rugger-buggers'!"
Rimmer claims that even some of the rugger-buggers converted to glam: the hooker in his direct grant school's 1st XVI ended up plucking his eyebrows at one party organised by Rimmer and his friend Polly.
For thousands of primarily heterosexual adolescents, the Bowie of Ziggy Stardust was a transgressive revelation - an incitement to nonconformity that changed their lives. Imagine, then, how it felt to be 15 and gay and to read Bowie's (albeit disingenuous) confession that he was "gay and always had been".
"I'll never forget seeing Bowie and Ronson with their arms round each other on Top of the Pops, singing "Starman"," says music critic Martin Aston, 40. "It did feel like my life changed. Even though I hadn't come out at the age of 15, it sparked off something in me - something which, sitting in my parents' living room, I couldn't exactly express. It was such a brilliant concept: this alien comes down and tells you it's all going to be different from now on. It was a brave new world."
"There's no point in beating around the bush on this," says Jon Savage. "Glam was finally some kind of free expression of male homosexuality in popular culture, five years after it had been partially decriminalised. The thing that had always been there in the music industry finally got a chance to appear in various guises. It became a fantastic pop mode, because there's nothing more amusing or intriguing for everybody than straight guys pretending to be gay. Glam opened a door and people could explore various things about themselves - the whole point was that sexuality is fluid. Like David Johansen of the New York Dolls said, `I'm tri-sexual - I'll try anything.'"
Even in America, which - despite the Dolls (and Lou Reed and Iggy Pop) - never "got" glam rock, the swooning androgyny and sheer fun of T Rex and co made inroads into the psyche of pop's underbelly. "It was fun and flamboyant and exciting," says Joey Ramone who, long before the Ramones, could be seen tottering down Queens Boulevard in New York in thigh-length boots and a pink jumpsuit. "I was definitely the black sheep of Queens! I got a lotta dirty looks. You were always walking around on the defensive: like, what the f*** you lookin' at? It was a very macho neighbourhood. I can remember going into this record store where everybody was into Led Zeppelin and Black Sabbath, and they really wanted to kick my ass for buying a Gary Glitter record. I felt like a total outcast, and I guess I was."
Asked if he thinks a glam sensibility still exists in American pop, Ramone points to Marilyn Manson as the natural heir to his one-time idol Alice Cooper. "For the younger kids, Marilyn Manson serves the same function as Alice did for me," he says. "I like the fact that Marilyn Manson makes people nervous. In these conservative times, it's good that there are people like him out there. Music today is so safe, and everybody's just kissing butt; at least Marilyn Manson is going against the grain."
Manson's shock value may have some validity in the homophobic US, but do we really need a glam movement in Britain?
"Anything that tells you you don't have to fit into any kind of stereotype is great," says Martin Aston, "but I don't think there's ever been a movement based on a revival. There just isn't the same need for a Ziggy Stardust today. If you're 15 and gay, you have so many more role models. Back then it was Larry Grayson and John Inman, and that was everything you didn't want to be. Yeah, you have babes on every men's magazine cover, but you also have glossy gay magazines, you have films, you have groups like Suede and Placebo. Drag is so pervasive today. Gay culture is such a part of the club scene. How many male torsos do you see in adverts every day? Everything is so much more open than it was when I was 15. Nobody could feel like they were `the only one' any more."
"I think camp has become much more acceptable in society, so glam doesn't have quite the same attraction," agrees Christopher Edwards. "The edges between masculine and feminine have been blurred anyway."
However spurious a glam revival may seem in the late Nineties, the memories of the music and the myriad outrageous styles live on. Just as the children of Ziggy Stardust became the stars of New Romanticism in the Eighties, so the spawn of Adam Ant and Boy George are once again bending genders and rifling through the dressing-up box. "That androgynous thing never goes away," says Dave Rimmer, whose 1985 book Like Punk Never Happened was all about the "new pop" of Culture Club and their ilk. "Why did thousands of teenage girls fancy Nick Rhodes?"
"Glam was about going out there and having fun," concludes Jon Savage. "I think it's been undervalued critically because it didn't appear to take itself too seriously. It had that horror of pomposity. But it wasn't like some little ghetto. It was full of vigour and full of life, and it bossed English pop music for two or three years."
Barney Hoskyns' `Glam! Bowie, Bolan and the Glitter Rock Revolution' is published next month by Faber at pounds 9.99. `Velvet Goldmine' is to be released in late October