MUSIC / Playing piano until the fingers get burnt: After 20 years in the music business, Billy Joel has a lot to teach about music. And a lot to learn about business.

Last week at the Logan Hall in the University of London, Billy Joel, who normally entertains people wedged in their thousands into sports arenas, sat on a stool in front of a handful of fan-club members and music students and took questions from the floor. Occasionally he jumped to the piano behind him to illustrate a point or to impersonate Elton John, which he does uncannily, or to show us the first song he ever wrote, which was terrible. The tickets called the event 'A Conversation with Billy Joel', but it was more like a counselling session for aspirant musicians with added jokes. 'I'm 44 now,' Joel said earlier that day at his hotel. 'It's time to start coaching.'

Joel has already conducted several of these sessions in America. But right now particularly there are reasons why he has advice to give and warnings to issue. Later this year, Joel will go to court to sue his own lawyer and his own accountant for malpractice. It is a case which, even more than George Michael's writ against Sony, could change the way artists and record companies in America do business, though it may not change Joel's attitude to attorneys in general, who are, he maintained during our conversation, 'the bane of my life' and 'like a tumour'.

'I have to have an attorney watching out for me all the time,' he said. 'But I've made enough money to hire another attorney to keep an eye on him. That would be my advice. Get an attorney - but as soon as you can, get another one to watch over him.'

Billy Joel has been making albums for 20 years. River of Dreams, which comes out later this month, is his 18th release for Columbia. Along the way, he has used his classically-trained ear to turn out middle-of-the-road pop standards - 'She's Always a Woman', 'Just the Way You Are', 'Uptown Girl'. But at the same time, as a businessman he has revealed himself to be almost uniquely tone-deaf. 'I've made a lot of mistakes. I've made some amazing, major screw-ups - but here I am, alive to tell the tale. So I must have done something right.'

Well, recently maybe. But his first management deal with a man called Artie Ripp proved, on closer inspection, almost to deprive Joel of the right to earn a living. The terms of Ripp's contract were so severe that jokers in the industry used to allege he was the Ripp referred to in the phrase 'a complete rip-off'. Only when Joel became successful did he have the clout to hire expensive lawyers and get himself extricated.

Then, disobeying the common wisdom about mixing business with pleasure, he employed his wife, Elizabeth Weber, as his manager - which made things tricky when they divorced in July 1982. 'She took a great deal from me - although most ex-husbands will be bitter about their ex-wives. But I gave away more than I should.'

After that, he put his ex-wife's brother, Frank Weber, in charge of his business - and got burned again. In 1989, Joel filed suit against Weber for fraud and breach of fiduciary duty. 'When I turned 40, I did an audit. Money had disappeared - he'd been losing money left and right, taking money, taking loans that I had never authorised, putting me in terrible investments - using me as a fire hydrant. They plugged their hose in whenever they needed money and - sploosh. I was Old Treadmill Bill - we'll send him out on the road again, have him go in the studio again.

'And this was a person I had trusted implictly. I had made this guy the godfather of my child - my brother-in-law. The thought that if anything had happened to me, my little girl would have had to trust this guy to take care of her future - it still makes me shake when I think about it. It shook me awake.'

Joel sued Weber for dollars 90m. In January 1990, a judge awarded him dollars 2m in a partial summary against Weber and later that year Weber's counter-suit for dollars 30m was dismissed. But Joel's discoveries about Weber were merely on the edge of something bigger.

'I felt like a complete idiot for not having known this was happening. Then I found I could never have known, because (he says) the accountants who I had hired to look after my interests knew that this was going on and never told me a word. And then the attorney who was supposed to be looking after my interests in the music business knew about this stuff and he didn't tell me either. So perhaps it was a conspiracy. Perhaps it was a conspiracy of silence. 'Let's not rock the boat - look, Billy's making money for us, everything's going fine, what do we have to mess things up for?' So I've turned around and I've sued them too.' Joel's lawyer is Alan Grubman, whose client roster includes just about every major American rock star and the record labels they belong to. 'Sounds like a conflict of interests to me - how can you represent the client and the record company? But that's part of the law suit. This is what is going on.

'Everybody is sleeping with everybody else,' said Joel, 'but the artist is the one that's getting screwed.'

Early signs were that 'A Conversation with Billy Joel' was going to be about as informal as a state visit by the royal family of a developing nation. Behind the piano, a reproduction of the new album's sleeve served as a backdrop. First on to the stage was the promoter Harvey Goldsmith, who delivered a small welcome speech. Only very special informal chit-chats require the involvement of top-grossing promotions agencies.

Then Paul Berger, the chairman of Sony Music UK walked on and gave us a standard-issue, after-dinner music business speech on Joel - 'real genius . . . pop balladeer . . . unmatched songwriting talent . . . depths of the human experience . . . social and political level . . . in excess of 75 million albums sold . . .' etc. And only then did Joel walk out from the back, bearded and in black, looking like Pavarotti after a strictly fluids-only diet, flashbulbs bouncing off him.

After that, though, the event became almost homely. The evening's single dumb question ('What did Mr Joel think about events in Bosnia?') was asked by a journalist. Everybody else wanted to know whether he arranged his own horns (he does), whether he still played classical (he does) and whether he still likes 'Just the Way You Are' (he doesn't, mostly because it was written for his ex-wife: 'People say, 'I got married to that.' Yeah, well I got divorced to it'). He talked about his management problems and took the opportunity to crack out some neat lines in his pugnacious New York voice. 'I was a draft-dodger, just like my President. Except I inhaled.' One fan, clearly overcome, prefaced her question with 'This is one of the greatest moments of my life.' 'Really?' said Joel. 'You've got to get out more.'

And so on for two hours. If the court case goes against him, there's a role for Joel in music college or stand-up comedy. But the chances are, he won't need to find out.

In the hotel he said, tight-lipped, 'If you ever go to these Rock and Roll Hall of Fame dinners, where they induct the Drifters and the Coasters, these old guys come out, they don't have a nickel. They don't have anything. And the heads of the record companies stand at the side and chuckle about how little they paid them. And I'm not going to be one of those artists.'

(Photograph omitted)