Creative tantrums and drug-crazed lifestyles only stopped the minority. Most got wrinkles and beer guts and rubbed along with each other rather well, actually. But doesn't it seem rather sad that pop stars should be out peddling goods long past their sell-by date?
"I think it's completely reasonable," says Andrew Collins, editor of Q magazine. "Plumbers don't fit three toilets and go into retirement. If you see a plumber in his fifties you just think that he will have gained expertise and be better than ever."
Bucks Fizz have toured for 50 weeks of the last year. Mike Nolan, one of the two original band members still in the group, speaks rather wearily from his hotel room in Yorkshire of the adjustment needed from being No 1 in the hit parade, to being a jobbing band on the road. "Bucks Fizz never split up. We've been going 14 years and the performing excitement is still there, though performing 'Land of Make Believe' all the time can become tedious.
"Once you've won the Eurovision you get known as a teenybop band, but no one ever forgets. All kinds of people come to see us now, but still no one will admit to buying our records."
Many musicians have never done anything else and, besides, they need the cash. "Few old pop stars have any money," says Alan Coltam, music agent since the early 1960s when, with great serendipity, he was social secretary of Liverpool University. "Most of them at the height of their success had the money all tied up with agents and managers and were pretty clueless."
There is a huge market for old-name bands to play corporate hospitality piss-ups, holiday camps, even bingo halls to audiences who have no desire to get sweaty over today's musicians.
The return to relative obscurity - sharing dressing-rooms, going to the supermarket and having to spell their surnames to journalists - can be rather a shock. Those who did not take themselves too seriously in the first place are best equipped to cope.
"Everybody has their turn," says Lee Sheriden from Brotherhood of Man, which is unusual in having all four original members still together. His soft tones are straight out of "Save All Your Kisses for Me", very Rod, Jane and Freddie. "We stopped recording in the early 1980s. It's a young person's business and we had a good run. But we never split up and we still do about 80 concerts a year, playing the holiday camps and so on. Obviously every artist hankers after being famous.
"We were very lucky we had nine hit songs, which is half a set. "Save All Your Kisses" was No1 in 33 countries. But the change in your status is so gradual that you hardly notice. We enjoy having less pressure now, but people often come up to us at the end and say: 'I didn't want to come, but I've really had a great time and I'll come again.' That's nice."
Sheriden sees the group as being good for at least another five or 10 years. "We will keep playing as long as there are people who still want to hear us. Of course we would love to record again if we were asked. We have material available if someone was interested."
A few years ago this would have been unthinkable, but the unabating nostalgia wave has already got 1970s stalwarts Showaddywaddy a new two-album deal for 1996. Showaddywaddy's combination of relentless party atmosphere and kitsch appeal means that their audience can have a great time without worrying that anybody actually thinks they take the group seriously. Original lead singer Dave Bartram explains: "We've had our tongue in our cheek for so long there's a permanent indentation." It's a lucrative joke. Wised- up Bartram, who identifies himself now as "at heart a businessman making a living", plays sell-out gigs making pounds 4,000 a time.
Bartram has faith in the cyclical nature of pop. He sees the rapturous reception Showaddywaddy receive in albeit smallish venues - "a mix of universities, corporate hospitality and scampi and chips in the North of England" - and thinks there could be great things ahead. "When I was young I was a closet fan of Roy Orbison, because crooners were so uncool. Then suddenly he was fashionable. It could happen to us."
Many old bands and singers have crept out of the woodwork with degrees of limited success. "People who gave it all up to become insurance salesmen are seeing that others are making it again," says Alan Coltam. "Twinkle does well, because there aren't many 1960s girl singers out there." Other bands are finding that even Butlins can be hard to secure. But with the right self-publicity, miracles can happen. Mike King, an agent, who books the cabaret circuit bands, says: "Lieutenant Pigeon are back on the road with only one original member. They only had one single - "Mouldy Old Dough" - and that was bloody awful, yet they're still commanding pounds 1,000 a show."
According to King, there are two crucial factors in the parallel universe of has-been bands. The recognisability of the band's name - often with the hits written on the poster to jog the memory - and the quality of the live act now. If it's no good the punters don't come back.
It's a tough existence and there's no room for Bowie-esque reinvention pretensions. The artists know that they must sing their greatest hits over and over again.
"Put it this way," says Maizie Williams, original singer from Boney M. "I don't sit at home and listen to "Brown Girl in the Ring" by choice, and one day I want to do solo stuff, but that's what people want to hear and, hey, it's working for me right now. Once you get dressed up and out on stage, it's still exciting." She issues a promise (or is it a threat?) "Boney M will always be with us from generation to generation, because everybody digs us. It's not like the music of today which a lot of people can't relate to."
PJ Proby knows he still has to fall off the stage every night. Les Gray of Mud has to be helped on to the stage these days but, like a trooper, he's still there - even if the audience only stop talking for "Tiger Feet".
A good performance can make up for lack of chart success first time round. The Beat Goes On, a 1960s nostalgia fanzine, conducts an annual poll in which the Merseybeats have just been voted best band. Never mind that it is hard to remember a single one of their songs - they give good Sixties.
The Beat Goes On publisher Mike Neal puts it like this: "They know their recording days are over, but the music is their bread and butter and they have a slick stage show. In the old days it didn't matter what the performance was like, because you couldn't hear anything above the screaming. Now the best of the old bands need to be able to entertain. They need a stage patter. They even have to be passable comedians."
Supply has begun to outstrip demand. Original bands have found themselves competing with smarter, younger, tribute bands. Such is the fuzzy world of pop reality that even when audiences are presented with a fake version they often cannot tell the difference or even care. Why pay pounds 50 for the real, old Rod Stewart when for pounds 30 you can see the new Rod and get a sit- down dinner thrown in?
Thus there are now three Boney Ms, each consisting of at least one original member. Rivalry between the bands is such that even the latest costumes are a deadly secret. There are two Bay City Rollers. And some bands are completely fake. "My friend saw The Four Tops in Ibiza, says Andrew Collins, "When I told her they weren't real she wasn't bothered. She said: "It sounded like the Four Tops."
Some individuals buy up the rights to a group's name, others merely steal. "We started taking bookings for a man who said he was part of the early 1980s band Tight Fit" (responsible for a falsetto version of "The Lion Sleeps Tonight") says agent Mike King. "All went swimmingly until a call came from the Big Breakfast wanting him to appear on the programme. He had to come clean for fear of a libel action."
But a name like Showaddywaddy will always sell so when does it stop? How old is too old? Showaddywaddy have a booking for New Year's Eve 1999. Dave Bartram will be approaching 50. Too old to click his fingers "Under the Moon of Love"? No way.
Any ageing pop star you ask cites Chuck Berry as the shining example of the septuagenarian performer. There is, it seems, no limit. "We will keep going as long as we are not an embarrassment," says Colin Gibb, founder member of the pop group Black Lace ("Agadoo-doo-doo, push pineapple, shake a tree"). He adds wryly, "After all, we always have been an embarrassment." Maybe pop music isn't quite so transient after all.