On Tuesday, Top of the Pops celebrates its 30th birthday with a lengthy blast from the past featuring a host of pop stars, including Michael Jackson, still snub-nosed and black, a pink-wigged Madonna desperately seeking an image before super-stardom, and Sonny and Cher, before the world discovered they were not really in love.
The programme is proof that almost anyone and anything, no matter how ridiculous, can be thought cool in its particular time. In the Glam Rock years, Gary Glitter's silver platforms did not look quite so ludicrous nor David Bowie quite so weird and emaciated. The evidence extends to the audience, with weedy lads in lurid tanktops and heavy-thighed girls in short white PVC dresses. The bits between the old footage will be filled by Smashy and Nicey, comedians Harry Enfield and Paul Whitehouse, who parody Top of the Pops' essential naffness, and old-timers Alan Freeman and Tony Blackburn.
But despite the celebrations and congratulations, Top of the Pops cannot shake off its detractors and their insistence that despite its longevity and 8 million viewers it must change or eventually die. Critics claim that by concentrating on the charts, the programme no longer reflects the interests of a CD-buying public with more diverse, fragmented music tastes.
The debate was fuelled this week by David Liddiment, new head of the BBC's entertainment group. Despite persistent rumours to the contrary, he insisted that the show, whose audience has halved since the 1960s, had a secure future. But he suggested that it might have to become less chart-based.
Tony Blackburn, a former compere, agrees that it has lost power and direction. 'In the 1960s almost everyone watched Top of the Pops. People don't realise there has been a revolution since then. There is more pop music on TV and a whole satellite channel devoted to it . . .'
Mr Blackburn is scathing about the decision two years ago to dump Radio 1 DJs and employ 'unknowns' . . . 'In my time Top of the Pops made you a national name. At least the DJs had something to do with music. No one knows who these guys are.'
But even in its heyday, Mr Blackburn found it difficult to take the chart business seriously. 'When you have to get excited about some single moving 'five sensational places' you have to see the funny side . . .'
Mr Liddiment's comments have clearly irritated Stanley Appel, Top of the Pops' producer, who will retire next month after a 20-year association with the show. 'Mr Liddiment . . . might find it is not so easy to change when he realises the limitations. We get knocked all the time because we have been around so long and are an institution. But it is unfair to compare viewing figures with those from the 1960s. Then the programme had no competition. The controller would be happy if all his programmes got an audience of 8 million.'
On Tuesday's show Pan's People, Ruby Flipper and the other dance troupes are conspicuously absent. Video killed off the dance troupes; some argue it will eventually kill off Top of the Pops.
But Steve Redmond, editor of Music Week, believes the power of Top of the Pops is undiminished. 'It is still absolutely vital to the music industry. It . . . has higher viewing figures than the Chart Show or The Word. Everyone wants to be on it.'