How Hollywood started in the shtetl - well, possibly

"Very odd," agrees Brownlow. "But mind you, not until The Great Dictator [Charlie Chaplin's 1940 satire on Hitler] was the word Jew used freely in films. Jewish producers were very nervous about it."

Jewish producers were cowardly about making Jewish films

Wright was very aware of this when he wrote his play. "Jewish Hollywood producers were terribly cowardly about making films about Jews," he says. "They didn't want to call attention to themselves. And of course during the McCarthy period Jews were equated with Communists, such as the Rosenbergs."

But we are getting ahead of ourselves. Wright's play is not really about Hollywood. And it is certainly not about American antisemitism. It is much more fun than that. Travelling Light, which is directed by National Theatre artistic director Nicholas Hytner, stars Antony Sher as Jacob, a shtetl timber merchant who in the play's made-up world becomes the first ever movie producer. He is the nascent Jewish Hollywood mogul, the forerunner of east and central European Jewish migrants such as Carl Laemmle who founded Universal, Adolph Zukor who created Paramount, Sam Albert and Jack Warner and Louis B Mayer, the man at the head of MGM.

Travelling Light is perhaps best described as a tongue-in-cheek homage to a culture that has been completely lost, but whose legacy continues to shine through the projectors of the world's cinemas.

The play is about a young man, Motl (Damien Molony) who returns to the shtetl too late for his father's funeral, only to discover that just before he died his father took delivery of a new-fangled gadget - a Lumière Brothers cinematograph. Jacob (Sher) turns up to have a portrait taken of his son and instead ends up commissioning Motl to make his first movie. Indeed, the big running joke is that Motl and Jacob invent the movies without ever meaning to. We see the first scene, the first edit, the first audience focus group (made up of shtetl residents) - we even witness the conversation that led to the invention of the cinema.

"It's hilarious. This group of argumentative Jews invent everything," says Hytner, who describes Travelling Light as a "parallel reality play".

"Yes, I sometimes forget that none of it is true," says Wright. "I'm certainly not saying that zooms and tracking shots were invented in a shtetl. It's a kind of joke, really. It's saying that if you had a movie camera in the shtetl community, you would very quickly get something like this."

For Wright, this is a departure from his usual subject matter of stories based on real-life figures such as Vincent van Gogh (for his play Vincent in Brixton) or Wallis Simpson (The Last Duchess, recently at the Hampstead Theatre). On the page, at least, this latest play is a warm and affectionate tribute to a culture which, it is perhaps not too fanciful to say, informed the American movie more than any other.

Wright's initially he had in mind writing about an imaginary Jewish filmmaker. "He had done war films and romances and musical comedies," says Wright, "and somebody asks him why after all these years he has never made a Jewish movie. And he says: 'I'll tell you a secret. All my films are Jewish'."

It is a punch-line that goes to the core of the play. An artist - such as Motl or even the South African-born Wright - has to be of free of his past in order to create. But ultimately he or she can only draw on experience.

So even though the first wave of immigrant Jewish filmmakers wanted to avoid Jewish themes in their work - "they made films about the country they wanted to belong to," says Brownlow - they may have been making Jewish films without realising it.

"I was reading a whole lot about 19th-century Yiddish popular literature," says Wright. "And a very popular story is the shtetl that has been overtaken by swindlers or criminals or violent men of some kind and then a hero arrives and kills them all. So High Noon is a Jewish movie after all."

But although Wright, who is not Jewish but displays a strong affinity for Jewish culture, is speaking half in jest about High Noon, his observation begs a question, albeit one that is almost impossible to answer. If, instead of the movie business Jews had gone into, say, the brewing business, would the movies that Hollywood made have been any different?

"That's a very interesting question," says Brownlow. "I remember the American critic Neal Gabler talking about the Jewish 'mother-love' movie. It all depends on who is writing the film. The first successful talking picture was The Jazz Singer and that was written by Samson Raphaelson, who was Jewish. But there were 'mother love' movies made by the Irish before that."

Still, Al Jolson's character in The Jazz Singer, Jackie Rabinowitz, certainly loved his mother. And although set on New York's Lower East Side and featuring a tormented Jackie who has to choose between his dying father's wish that he become a cantor or a life in the theatre, the film also serves as an allegory for all the Jews and Jewish filmmakers who escaped their ghetto pasts.

Until someone makes the film about the shtetl Jews who became Hollywood moguls, it will have to do. In the meantime, there is the Travelling Light, the play.

"I should think it would be a very good movie," says Wright.

'Travelling Light' is at the National Theatre until March, when it goes on tour to Salford and Leeds. Tel: 020 7452 3000.