'At least this fellow Wagner gets a tune going'

"Plink. Plink. Whaaarh. Glock." In a crowded Covent Garden cafe, Polly James is doing an impression of the composer Schoenberg. "Gleek. Plank. Twoing." We have come a long way since The Liver Birds. My only other musical memory of James is her singing the theme song to the Seventies sitcom ("You dancin'? You askin'?") that she and Roger McGough chorused, a catchphrase parroted in every disco in the country. Then, the Lancashire-born actress played Beryl, the sparrow-like gadabout who took life less seriously and dressed more tartily than her posher flatmate, Sandra (Nerys Hughes). Now, aged 55, she is talking about Wagner to publicise her directorial debut. "Listen." She leans forward conspiratorially. "I might have had to learn about Schoenberg. That would have really done my head in. At least this fellow gets a tune going now and then."

This isn't another story of a theatrical talent taking on opera (though, with her seasons at the RSC, a rattlebag of awards, even a triumphant assault on Broadway with Tommy Steele in Half a Sixpence, James has proved she has a talent that stretches far beyond sitcom). There isn't much music in The Twilight of the Golds, which opens at London's Arts Theatre in June, and what there is is taped. Jonathan Tolins's tragicomedy isn't actually about Wagner either. Rather, it uses the legends of the Ring cycle to illustrate a debate about genetics, abortion and homosexuality.

David Gold (played by Barbra Streisand's son Jason Gould) is a gay set- designer at the Metropolitan Opera in New York. When his pregnant sister Suzanne takes advantage of a revolutionary antenatal test, it reveals that her unborn son has a gene that predisposes him to be homosexual. Should she have a termination? The question threatens to tear her family apart.

Woven into this occasionally clunking issue-based drama, are the Wagner parallels - drawn by the waspish David, and reinforced by a design that surreally combines a New York sitting-room and the set of Gotterdammerung. Beryl would have been out of her depth. Polly - though she didn't choose the play herself but was gifted it by the producers - is undaunted. She's also keen to scotch the suggestion that there's anything incongruous about her directing this play.

"It's not a gay play. It's not a Wagner play. It's a play about a family. It's a Jewish family. I'm not Jewish. I'm a Catholic. I was brought up in a convent. But I can substitute one kind of pressure for another. Family life is family life."

But, in any case, she has flung herself into research. "I've got to know what the playwright's referring to. The Ring is played in the car, and it's very, very, very heavy going." What would she normally listen to? Elkie Brooks, Roberta Flack, Radio 4, football on Radio 5 Live, La Traviata. "Oh - and Elton John - I love his lyrics." She thrusts her arm high above her head. "I've a stack of Wagner tomes this high by my bed. It's a very rarefied subject. There are people who've heard every Brunnhilde, every Siegfried. Hell of a job, the Ring, isn't it? Twenty nine hours!

"But I am musical. I was brought up playing the violin and the piano. And there's something about the huge canvas the story covers, from the stealing of the gold, through all the battles... You have to like the size of it: it's not like you and me sitting here. We'd have to hang from the ceiling and swing about to give it the hyperbole it needs."

There was something prescient about Tolins's work when it was first staged in the States, in 1993. Just as the play prepared to transfer to Broadway, a scientific study claimed to have found a physical cause for homosexuality. Developments in genetics continue apace. This year has seen the arrival of Dolly the sheep, and James Watson, one of the scientists who discovered the double-helical shape of DNA, has told The Sunday Telegraph that - technology allowing - aborting a baby with a "gay gene" would be morally acceptable. Meanwhile, where science has led, Polly James has followed.

"This is invaluable," she says, taking from her bag a newspaper article headlined, "After the Black Sheep, the Pink Sheep". "Now, do you know how they clone? This is the simple diagram that tells me. Here's the perfect sheep. Now they fuse it with the mummy sheep's cell and then... Anyway, an actress friend of mine said, 'It's terrifying.' I said, 'I can't imagine that somewhere in the world they're not cloning little peeps. They wouldn't tell us, would they?'"

If, after this kind of dedication to her new role as a director, people still insist on blurring Polly James the director with scatty Beryl, that's their problem. "The Liver Birds has given me a lifetime of goodwill," she says. (The sitcom's ill-fated resurrection last year gave her the money to take on this project, too). "But it's the one image of me that sticks in everybody's mind. I can't do anything about that. They have to make the leap."

'The Twilight of the Golds' is at the Arts Theatre, London WC2 from 17 June.

Booking: 0171-836 2132 AT