With their gold-lamé suits and leopard-skin posing pouches, Boney M helped bring a much-needed touch of the exotic to Britain in the gloomy, crisis-hit days of the late 1970s. And for the scantily clad, German-manufactured disco stars, 1978 was to be their high-water mark, a year in which they sold more than three million singles in the UK as well as notching up a platinum album.
But now the controversy over one of the great sleights of hand in pop music history has been reignited. It is claimed that hundreds of thousands of Boney M fans ended up buying the same single twice that year.
A documentary due to be broadcast on BBC Radio 4, chronicling the all-but-dead art of the B- side, reveals how the record company doubled its money from the seven-inch "Rivers of Babylon" when it was remarketed with the flip, "Brown Girl in the Ring", as the A-side.
The presenter of the programme, Anthony Barnes, believes the revelation will send thousands of fans scurrying to their lofts to rifle through their old vinyl collections to see if they unwittingly paid twice for the same songs.
"It was probably the greatest rock'n'roll swindle of the 1970s," he said. "Thousands of people bought the single, little realising they already had the track. If only more people had taken a little more time and effort to listen to the B-side, they could have saved themselves the 79p they paid at the record counter."
Ardent fans of the group are probably aware of the controversy – the issue has been discussed on online forums dedicated to the band – but few mainstream music buyers are thought to realise their mistake.
The re-working of the traditional spiritual "Rivers of Babylon" had already topped the charts for five weeks in the UK, when it slipped down to No 20. DJs were then persuaded to start playing the flip side, featuring the traditional Caribbean nursery rhyme "Brown Girl in the Ring" which helped power the group back into the top 10 and made the single the then second highest-selling of all time, just short of two million copies.
The band went on to seal a year of success with a million-selling Christmas number, a cover of Harry Belafonte's "Mary's Boy Child".
Chris Lowe and Neil Tennant of the Pet Shop Boys, who were widely admired for the quality of their B sides, told the programme, Killer Bs, they believe the dividing line between a successful A-side and a forgotten B is surprisingly thin.
"I don't think A and B is about quality – it's about ability to get on to radio," said Lowe. "The point about a single is it needs airplay so you get the album too. It's the commercial radio factor that decides A and B."
Tennant said the rules of making records had changed after the introduction of CDs and downloads which in effect rendered the supplementary track redundant. "When we first started making records in the 80s, the A-side as now would be on the album, the B-side not," he said. "If you're expecting a fan to buy a single they'll already have the A – it's on the album – so in a way they're buying it for the B."
Famous flip sides
* Gloria Gaynor and her anthem to the jilted lover "I Will Survive" are now world-famous but in 1978, record company bosses fancied her cover version of The Righteous Brothers' "Substitute" instead. DJs did the flip and created history the following year. The all-female band Clout went on to have a worldwide hit with "Substitute".
* Originally included as the B-side to "We Are The Champions" in 1977, "We Will Rock You" was never intended as more than a B-side, a short overture to the album News of the World. In the United States it was released as a double A-side.
* "How Soon Is Now" saw The Smiths at their haunting, soaring, enigmatic best. Yet the track was originally only a B-side on the 12-inch version of "William, It Was Really Nothing", in 1984. It was eventually included in the compilation Hatful of Hollow and issued as a single in its own right.
* "Father and Son", even before it was covered by Boyzone in 1995, was probably Cat Stevens' best known song. However, when it was released in 1970, Island records only thought it suitable as a B-side to the hippyish "Moon Shadow".
* For years Noel Gallagher delighted in telling interviewers that "Some Might Say" released in 1995 defined the Oasis sound. He was later to change his mind and describe its B-side "Acquiesce" as the band's greatest track.