There is embedded in our culture an oft-repeated story about pop music and it goes something like this: a brilliant talent, usually from a working-class background is discovered by a wealthy agent who exploits the hitherto unknown hopeful to the hilt. Then, because the talent doesn't read or understand the small print in the contract, he, she or they end up producing material for which they get paid very little if anything at all, while the parasites who signed them continue to rake in the proceeds.

Or so the story goes. Oh, there is one other element to the legend. The agent is often Jewish.

Two recent stage productions have latched on to this element of what might be called a myth. In Epstein, a small but powerful play by Andrew Sherlock subtitled The Man Who Made the Beatles, the Jewish fixer is centre stage. While in The Kinks' new musical, Sunny Afternoon, a conspicuous sub-plot of the show concerns Austrian refugee Edward Kassner, the man who made The Kinks.

The show is driven by Ray Davies's music, of course, but it still gives Kassner (played by Ben Caplan) space to tell his refugee-made-good story. He survived the Holocaust. His family didn't. Next to the show's two English toff buffoons who were first to represent Davies and The Kinks, Kassner comes across pretty sympathetically.

Yet there is a moment in the show that might make some people shift uncomfortably. It illustrates how money is siphoned off to various promoters, distributors, managers and agents, and it shows them all standing in a line with wads of cash being passed along until the money reaches Kassner. None of the cash gets to the Kinks.

Now, whether it was necessary to show a Jew in the role of, depending on your interpretation, mastermind manager or arch exploiter is a matter of opinion. Clearly, both in the show and in real life the buck really did stop with Kassner.

However, in the Brian Epstein play there is a rather different take to so-called backstage Jewish control. According to Sherlock, Epstein deliberately left his first contract with the Beatles unsigned just so they could leave whenever they wanted. Why? "Perhaps it was not wanting to be seen as the tightfisted Jew," says Epstein in the play.

Back in Sunny Afternoon, it was another Jewish manager, the American Allen Klein, to whom Davies turned to extricate his band from the contract he had signed with Kassner. However, the musical doesn't make clear that Kassner Music still has a major interest in much of the Ray Davies catalogue.

"Let's put it this way. About a third of the music in the show is published by our company," says Kassner's son David who now runs his late father's business.

But is it fair to portray agents as Jewish exploiters of talent? Certainly Jews were –and are – as well represented in this form of showbiz as any other. But Jewish business nous wasn't always unwelcome.

Indeed, it was considered by some gentile stars to be desirable. The well-known Hollywood and music talent agent Shep Gordon - about whom Mike Myers recently made the documentary Supermensch - was asked by Jimi Hendrix if he was Jewish. Gordon said that he was, to which Hendrix replied that Gordon should be in music management. Hendrix went on to became one of Gordon's clients.

It's worth noting that Gordon is known as one of the nicest guys in showbiz, though being "nice" is not what managers are generally known for. At the other end of the spectrum, and on this side of the Atlantic, there was Don Arden who, although he went to the Royal College of Music, had business methods that were sometimes more mugger than maestro. His acts included Ozzy Osbourne, an association which led to Arden's now famous daughter Sharon, getting married to the rock star.

As for his business methods, one story relates just how persuasive Arden's negotiating skills could be: he turned up at the fourth-floor office of impresario Robert Stigwood and, with his heavies, dragged Stigwood to his window and threatened to throw him out for encouraging one of Arden's acts, The Small Faces, to move management. The heavies went further than even Arden expected when they pulled Stigwood from Arden's grasp and hung him upside down from the window.

Perhaps unsurprisingly, David Kassner says real life was more complex. "We're talking about the '60s. You have to take into consideration that, for every artist that becomes successful, there are hundreds, if not thousands, that didn't earn money and didn't have the talent to achieve anything. But the only ones who complained of an imbalance of power were the successful ones. People don't seem to understand the risks that have to be taken in order to sift out good from great. The public don't want good. They want great. And [as a manager] you don't know right away what you've got. Artists can't judge for themselves. They need people like my father with the drive, the determination, the connections and the money to get them started. People had to take risks; had to back their judgment - and what came forth was this fantastic body of music that the whole world is enjoying."

It was, says Kassner, a pioneering time. "There was no rule book. And it's fine for people to say this contract wasn't right and that deal wasn't right. Nobody knew.

''And it certainly wasn't a Jewish club. My father started a music publishing company in 1944 and encountered plenty of antisemitic resentment." Manchester-born Arden changed his name from Harry Levy for the same reason.

So it seems the real unsung heroes of the rock and pop industry were often those who didn't sing. They are often portrayed as the villains of an industry which, let's face it, is full of exploitation. There's a scene in Sunny Afternoon in which Ray Davies is reminded by an African-American union representative that The Kinks' music is rooted in black music. Everyone is exploiting someone and rarely does anyone get the recognition they deserve. Kassner Junior reckons his father did. "Ray recognised that my father was the first one to see he was a genius," says Kassner. "Even before Ray realised."