Bob Dylan knocks on the door of a house. He's looking for Dave Stewart of Eurythmics and this, he thinks, is the right place. A lady answers the door and Bob asks if Dave Stewart lives there. She nods, telling him Dave has popped out but will be back soon, and he goes inside to wait. An hour later, Dave Stewart walks in, not rock star Dave but Dave the plumber, whose house this is. Rock star Dave, it turns out, lives on the next street down, and plumber Dave (a massive Dylan fan, coincidentally) is a little surprised to find the voice of a generation' on his sofa in his living room having tea and biscuits with his mum. Bob sheepishly makes his excuses and leaves.

Is this true? Probably not. But just like Cliff Richard teaching Guns'n'Roses' Slash and Ozzy Osbourne the right etiquette for how to greet the Queen or George Jones driving to town to get a whisky on a lawnmower to get a whisky because Tammy Wynette had hidden the keys to all five of his cars, it's such an unlikely and amusing picture we relish the possibility that maybe, just maybe, it really happened.

Other rock myths aren't quite so harmless though - Mick Jagger retrieving a Mars Bar from Marianne Faithfull's vagina (a story strongly denied), or doctors treating Marc Almond finding a pint of semen in his stomach (also strongly denied) are just two of the highly questionable rumours that have circulated.

Radio presenter and co-creator of Dead Ringers Jon Holmes has collected many such stories (the amusing, the preposterous and the frankly disturbing) together in a new book, Status Quo And The Kangaroo. The titular story (or title track', as Jon calls it) recounts the time the mighty Quo were travelling across the Australian outback when they hit a kangaroo. Lumbering off the bus, they saw the poor marsupial lying still on the road and assumed it was dead. What to do? Dress him up in a denim jacket, shades and bandana and pose for a photo, of course. But when the camera's flash went off, the kangaroo (only dazed, after all) leapt to its feet and hopped off, still wearing the jacket, shades and bandana. The band thought this was hilarious until they realised the keys to the tour bus were still in the pocket of the jacket the kangaroo was wearing as it bounced toward the horizon. D'oh!

And there's the time at Wembley Stadium when one of Celine Dion's entourage was clearing people from the route to the stage, because her diva-ish boss refused to be looked at by anyone prior to performing. When a stubborn crew member charged with looking after some equipment refused to budge, two bodyguards were brought in to remove him. But he wouldn't be defeated so easily - he climbed up some rigging and sat quite comfortably out of reach, reading the paper. Half an hour after she was meant to start performing to 70,000 fans, Celine was forced to walk to the stage with a blanket over her head (My Heart Will Go On, But I Won't, this chapter of the book is headed).

Then there's the story that the musician behind the smooth sax tones of classic' Baker Street is none other than Blockbuster's Bob Holness (I'll have a B flat, please, Bob'). Or that, when asked for a reaction to the death of King Hussein of Jordan, Mariah Carey mourned the loss of the greatest basketball player of all time.

When it comes to apocryphal tales about rock and pop stars, nothing's too weird: Charles Manson auditioning for The Monkees; Michael Jackson bidding to buy the remains of the elephant man; Van Halen demanding their rider included a jar of M&Ms with the blue ones taken out; Freddie Mercury's parties catered by dwarves carrying trays of cocaine (But none of these things actually ever happened. Probably.) Why are we so fascinated by such stories, when so many are clearly nonsense and, even if they were true, there would be no way we could know for sure? Jon's theory is we're all living vicariously. "We all like to live our own mundane lives through the glorious, if rather seedy eyes of rock stars. That's what rock stars are for."

This could certainly be said of a young Mick Wall, long before he became a renowned music journalist. "It was so exciting," he says. "I remember reading books about Rolling Stones tours and thinking, What a life.' Instead of going to dreary work every day, you get to do a show, jump in a limousine, get groupies, snort coke, stay up all night listening to music As a young person, that's very appealing."

There's also an element of celeb-bashing though, says Holmes, a jealousy-fuelled delight in believing that the glamorous stars singing on television don't really have such perfect lives. "I guess it's moved on to the Heat generation who like to look at Liz Hurley's sweat patches or someone's nipple falling out - anything that brings stars down a peg or two." Successful women especially, from Mariah Carey to J-Lo, who seem to have it all (the money, the body, the life), are routinely followed by disparaging rumours about their outrageous demands or behaviour, perhaps to make the envious feel better by believing these people are really miserable or, even better, perhaps a little mad.

The rock-star-collapses-and-has-a-pint-of-semen-pumped-from-his-stomach' myth, most commonly attached to Marc Almond, doesn't say good things about society either. The same basic story has been spread about several other pop stars (Britney Spears, Jon Bon Jovi) but is most strongly associated with gay stars, such as Erasure's Andy Bell, Elton John, Andy Warhol, and androgynous gender-benders such as David Bowie. This homophobic slurring has certainly helped perpetuate the idea that all gay men are sex-crazed perverts routinely engaged in sordid orgies and partner-swapping. It makes you question why people have been so keen to spread this story about these men in particular, and why many are so quick to believe it.

There are other times though when rock stars themselves make it easy for us to believe these stories could be true though - a little bit of craziness' never did a rock career any harm. Marilyn Manson talks openly of his collection of stuffed animals and his unborn foetus in formaldehyde, called Ludwig, in a way that - deliberately - encourages speculation about his lifestyle and personality. Ozzy candidly discusses the times he really did bite the head off a bat or tried to strangle his wife Sharon Osbourne while on drugs. Knowing certain outrageous stories to be true softens us up to believe the other rumours we hear, no matter how outlandish. Keith Moon, for example, lived a life so full of rock excess and wild pranks that it's almost possible to believe any story that's printed about him.

Everyone from Puff Daddy to Morrissey has their personalised stories, but for the real myth-makers we need to go back to rock 'n' roll's glory years, when bands such as Led Zeppelin, The Rolling Stones and The Who reigned. "If something's gonna happen, rock 'n' roll is the place where it's allowed to happen," says Wall. "I've been in this business nearly 30 years and when I first went out on the road, I'd have been very disappointed if we didn't all get slaughtered and if women and drugs weren't involved. If someone wanted to drive a limousine into a swimming pool, that would have been fantastic.

"The other thing people love about that time is it's so un-PC, so un-reconstructed, so pre-Aids and pre-internet. In the Sixties and Seventies, bands like Zeppelin had not existed before. Private planes from show to show, playing in massive stadiums, coming off and having heroin dealers and teenage groupies None of that had happened."

Is the mythological age over now, or is it still possible for bands to create their own enduring legends? Perhaps today's bands play it too safe, their fancy tour buses with DVDs and games machines diffusing the boredom that made throwing TVs out of hotel rooms so appealing.

Or perhaps they're just better at hiding their misdemeanours, the importance of touring America (not easy with criminal convictions) and the money to be made from advertising and product endorsements providing big incentives. "Clearly, there are a lot of people going into music as a business," says music biographer Clinton Heylin. "Many of them have business managers before they have people who'll actually help them make good music. And also they're much smarter about keeping things secret, much more aware of the deception needed to do that."

There's more to it than this though. Aids has made such Sixties-style sexual abandon impossible or at least reckless. Also, the idea of men in bands taking advantage of teenage girls now just seems an abuse of the position - lechy, misogynistic and a bit sad.

"The attitude of British bands in the Sixties and Seventies does seem very sexist now," agrees Heylin. "At the time, it was just working-class English yobs being let loose in America with some free-spirited females making themselves readily available. It's hardly surprising they embraced that. But that kind of thing just wouldn't be interesting now. You'd have to have six females, three donkeys and a kangaroo to make a news story these days." Drugs, too, have lost the otherworldliness they once had. "When The Stones or The Who did drugs, it was out of reach of the man on the street," says Holmes. "Nowadays, you could spit and you'd hit three people who take cocaine at the weekend. People like Pete Doherty aren't really special' now. You want to see someone on heroin? Look at a junkie on the street or go into a crack house - very glamorous."

Pete Doherty seems to have got up a lot of people's noses. Everyone I spoke to singled him out as the antithesis of rock 'n' roll. "There are bands trying to act like they're in some weird rock-historical loop," says music writer Simon Reynolds. "Pete Doherty seems to be living out a script. He's taken the rock bad boy thing but adapted it for the reality TV age. Bands like Led Zeppelin had a fantastic aura of mystique about them, whereas Doherty's turned his life into a blog." Wall agrees. "Bands like The Stones and Led Zep wrote the rule book. Now we have the rule book and it's dusty and well-thumbed. That's why Pete Doherty is such a sad, pathetic figure - because he's doing this stuff but there's no substance to it. He's living the life but I couldn't name a single song he's written, the way you can Brown Sugar, Stairway To Heaven, London's Burning Long before it got interesting, the whole Kate Moss and drugs thing took over. That's all we know him for and it's really tedious."

If there is a shortage of new tales of rock excess, perhaps it's because bands find the idea of acting up just to be rock 'n' roll, taken to almost parodic levels by the likes of Motley Crue, boring. "It's become so clichéd and conservative - not shocking at all," says Reynolds. "That's why I think the coolest band in the world are Radiohead. There's a great story about a band wrecking a dressing room. Radiohead were so embarrassed by the band's behaviour, they tidied up after them.

That's authentic. Even Bobby Gillespie, for all his rock 'n' rollness, has said that Primal Scream have never trashed their hotel rooms because they know it's some badly paid woman that will have to clear it up. In a weird way, the subversive thing to do is read books on tour and go to bed early. That's the only subversion left in rock 'n' roll." Hopefully, that isn't quite the case. But is there anyone out there capable of picking up the baton and creating the myths of the future? "I had high hopes for The Darkness for a while," says Holmes. "But that fizzled out, and then Justin was going to be on the Eurovision song contest. So disappointing."

Wall is equally sceptical. "To me, there isn't anybody substantial. I mean, Robbie Williams? It's all a bit apologetic and sad. It's not defiant in the Keith Richards sense."

To be fair, modern rock stars have a lot more working against them in the myth-making stakes, with whole magazines and TV channels dedicated to exposing' every detail of their lives, and editors and programme-makers prepared to pay ever larger sums for insider information. There are bigger temptations, too, for celebrities themselves to reveal all, especially the monetary incentives for tell all' autobiographies, newspaper exclusives and reality TV confessions'. Our media-saturated culture means there's now far less space for rumour to grow into myth.

This has only been accelerated by the arrival of the internet: both a help and a hindrance to the propagation of myths.

With such a huge amount of accessible information and video footage cropping up instantly on sites such as YouTube, modern celebrities are overexposed. It's impossible to retain that same aura that once made Led Zeppelin so mysterious. But the internet is also spreading stories quicker and further than ever. Online, there are pages dedicated to the claim Marilyn Manson used to play Kevin's nerdy friend, Paul, in The Wonder Years. Or that peace-lovin' country singer John Denver was formerly a US sniper in Vietnam with 72 kills under his belt.

One of the most recent rumours flying around the Web claims Pete Doherty was the invention of pop anarchists The KLF, his whole persona and career (The Libertines, drug abuse, burglary, Babyshambles) a giant elaborate hoax. It's a perfectly constructed piece of misinformation that's now, no matter how unlikely, out in the public domain. According to a statement by KLF member Jimmy Cauty, subsequently copied on to countless websites, the stunt was designed to show "the frailties of our celebrity-obsessed culture" and prove that anyone, regardless of talent or intelligence, could become a star. And the dupe they reeled in to play Pete? Really an obscure Buddy Holly impersonator called Trevor McDermott, more used to performing at holiday camps.

Do you really believe it? Of course not. But let's face it, you kind of want to, don't you?

Status Quo And The Kangaroo by Jon Holmes is out now, Michael Joseph, £12.99