ONCE, a nation danced to their tune. Now, old and down on their luck, some of the biggest names from America's golden age of pop music are suing recording companies and their own trade unions for cheating them out of hundreds of millions of dollars of pensions and health insurance benefits over the last 35 years.

Take, for example, Sam Moore. Back in the 1960s, he was one half of the hugely successful Sam and Dave duo. But despite No 1 hits such as 'Soul Man' and a prestigious Grammy award, he has dis covered that the pension account which should have fattened in his years of celebrity contains less than dollars 2,300 ( pounds 1,560). For him and perhaps thousands of others, a lawsuit under way in Atlanta offers a hope of belated recompense.

The case brought by Mr Moore and a dozen fellow plaintiffs seems simple. Under a 1958 agreement with Aftra, the recording artists' union, the companies promised to pay in a proportion of royalties and other earnings into a health and retirement fund operated by the union. Instead, the lawsuit claims, they understated earnings and often failed to pay into the fund; the union did nothing to stop it.

How much money went unpaid is contested; the companies say a few million dollars at most is involved. But plaintiffs' lawyers say dollars 750m may be owing. The suit is seeking dollars 4bn for the 'tragedy of human suffering'. It, moreover, may be broadened into a class action, meaning as many as 70,000 entertainers who could be entitled to damages.

Tracking individual pension entitlements will be difficult in a business as transient and turbulent as rock music. Even so, the singers appear to have a fair chance of winning.

For some, such as Mary Wells, it will be too late. In the 1960s she was a Motown goddess; her hit 'My Guy' was an anthem of a generation. But when she died two years ago, of throat cancer at the age of 49, Wells was penniless.

Some 35 companies are among the defendants, accused of breach of contract, violation of pensions laws and fraud. The most damaging assertions are from Frederick Wilhelm, a former manager of the artists' pension fund. Before 1989, he says, the fund was never audited. 'Rarely a month went by when I didn't come up with a Mary Wells situation.'

'My Guy' still brings in royalties. But estimates say 70 per cent of the 2 million people working in the music industry, like Mary Wells, have neither health insurance nor pensions.