Whether working at the ENO, the RSC or the London Palladium, Steven Pimlott is equally adept at putting the theatre back into opera or bringing out the music in a spoken line. No wonder he is most at home in musicals.

Not many people have a CV boasting productions of both Carmen and Carmen Jones. Throw in Mozart and Verdi, Sondheim and Andrew Lloyd Webber, and you're getting close to the diversity of director Steven Pimlott. And that's before you start on the plays. Ignoring his forthcoming musicals, Dr Dolittle, led by no less a figure than Phillip Schofield talking to the animals, and Cy Coleman's new A Star Is Born - not to mention a revival of his La Boheme at ENO in March - 1998 will also find him bringing his RSC staging of Tennessee Williams's Camino Real to the Barbican and directing world premieres by Robert Holman and Phyllis Nagy. This man is positively promiscuous.

The late Isaiah Berlin divided artists and individuals into two camps: hedgehogs and foxes. Dante, Ibsen and Proust are hedgehogs, pursuing a single universal organising principle; while Shakespeare, Moliere and Joyce are foxes, seizing upon the essence of a wide variety of experiences and objects for what they are in themselves, rather than seeking to fit them into a unified inner vision. It's fair to say that the very nature of working on other people's plays means that few directors turn out to be hedgehogs, but Pimlott would appear to be foxier than most.

Or is he? True, his almost absurd workload means he'll hardly have a day off between now and next August, but having reached fortysomething, he's taking stock, stopping down the lens and focusing his vision. It all stems back to an incident a couple of years ago when he was working on his unusually fluid, updated Boheme at ENO.

It happened at the "model showing", a standard opera house procedure where director and designer explain their vision to the company. "We were talking about why we were doing it like this and, at the end, the repetiteur [vocal coach] - who shall remain nameless, may she rot in hell - said, `Has it ever occurred to you that people might just come to listen to the music?' And you think, `Oh, why bother?' But, you know, I'm not all that confident she wasn't right."

Were he part of the fashionable wave of theatre directors who have recently flirted with opera for the grandeur of its design and budgets, such a remark might be understandable, but coming from someone who trained at ENO in the early 1970s, it's downright peculiar. He warms to his theme. "It's a controversial thing to say, but I do think that opera is about the conductor, not the director. That's not to say there isn't a huge art in directing opera well. Indeed, I think the director's job is much harder than the conductor's because, on the whole, the music has fared better than the stage conventions in which the piece was written. Look at Verdi, for example. This really is controversial, but it's difficult not to see opera direction as glorious, brilliant, fabulous, interpretive window-dressing. That is not to deny that great opera directors don't get beyond that, but to get beyond that is so difficult."

Fighting talk. In the politest possible way, he's kicking against the cumbersome, unwieldy machinery of opera production that gives the director little or no say in casting (a process in the control of the music staff) and puts final rehearsals in the hands of the conductor.

"Frequently, your job is bringing the singer to base-line. Never mind directing, it's actually just about getting someone across the stage, to sit down or get a drink. Personally, I find life exciting in a rehearsal room with theatre people. But with opera, what is exciting is working with the designer and dreaming it all up in the model box; that's great fun. The reality is that it's rare that anything happens in an opera rehearsal room. I don't find that very interesting, therefore I don't think I do it terribly well."

In fact, he's equivocal about the whole business, especially in Europe, where he has just directed Verdi's Macbeth. "The publicity, the front covers, the front page-ness of it! One tends to think of it as a medium of sensuality rather than cerebrality. Not in Germany. It's alarming, daunting."

He feels ambivalent too about the popularisation of Pavarotti singing "Nessun dorma" et al but equally unhappy with opera's bourgeois cachet. "All the opening-night nonsense of hair-dos and jewels has filtered to the surface with the recent Covent Garden stuff, the notion of opera as a gentlemen's club. And there's part of you that's bolshy and thinks, `I don't want to be some fucking liveried servant providing you with entertainment between your smoked salmon and whatever'."

His decision to turn his back on opera is balanced by his passion for that most popular of theatre forms, the musical. His earliest experiences of theatre came from acting out the Hollywood films of musicals like The King and I. Above and beyond the very direct emotional appeal of a musical's way with a story, he believes the thrill of directing them is quite distinct. "The people you work with, whether conductors or performers, are enormously expert. They are virtuosi. But the real charm of a musical is that, to a certain degree, it is right or wrong in a way that a play or an opera isn't. This is to oversimplify, but it makes its point or it doesn't. You cry at that moment or you don't, you laugh or you don't. It's not easier, but there's a clarity about the planning and the experience and an honesty and a vulgarity which I can relate to. It's difficult not to be hierarchical about one's achievements, but I am proud of the musicals. They are important and I don't have a problem saying so, and I slightly do with opera."

Pimlott's worldwide hit production of Joseph and His Amazing Technicolor Dreamcoat in 1991 changed his life completely - his percentage means he need never work again - but it wasn't just financial. More surprisingly, the show's precision, control and theatricality led Phyllis Nagy to offer him her coolly poetic play Butterfly Kiss. In the first volume of her published plays, she describes it as her favourite production experience. He followed this exemplary, magnetic piece of direction with Nagy's thrillingly ambitious The Strip and is about to open her latest, Never Land, at the Royal Court.

Tactfully refusing to name names, he alludes to letter-writers who leave the actors to flesh out texts which often have little to recommend them but their dialogue. "With Phyllis, the challenge for the actors is to go towards these people. Her plays are like classical texts. Everything is there in the material. I never know with her how much is sheer instinct and how much is head-work, but there's a fantastic sense of structure and playing with tradition. Never Land is a three-act play, and a classical one at that. It unveils itself and the strands, the music of it... Musical metaphors really apply in her work - it is as if there are leitmotifs and rhythms. You have to hear her plays."

On a literal level, Never Land is startlingly topical, a passionate story about Europe and a French family who, against all the odds, yearn to become English. But beneath the dramatic struggle between personal choice and destiny, Pimlott discerns more. "I have found myself saying to the actors, `This speech is a bit like Bach', and Phyllis has turned round and said, `I was listening to Bach when I wrote that.' Or I described the end of the first act as being like the end of Act 2 of Figaro. She said she was listening to that too. It's like the Twilight Zone," he laughs.

He finds it hard, nevertheless, to discuss his own approach. "You never know how anybody else goes about it. Everybody else's rehearsal room is as secret as their sex life. Even more than their sex life in a lot of cases..." He admits to being quite instinctive, responding to the moment. "In the old days, I plotted and planned. Whether it's laziness in not doing homework or just somehow trusting the acting I don't know, but now it seems to me that, before you can conduct the play, you have to have enabled the actors. They all have different ways of working, and you've got to get them firing on all cylinders so that they are being creative and making it their own. Then you can begin conducting."

The conducting analogy points to the unifying theme in his uvre. He concedes that, even in the plays, "music is always there for me". It reveals him as less of a fox and more a somewhat unlikely hedgehog. Certainly it is what makes him such a fine director of Nagy's highly patterned plays. He loves the "arias" for the three main characters, the "duets" in terms of the language, ideas sometimes linked through assonance and connections of sound. He speaks eloquently about the clarity of her vision.

"Her voice is her own. It's not someone harping on with only the voice of the author - that's boring - but beneath the delightful imaginative exploration of what it is like to be other human beings, there is the particular, idiosyncratic voice of the author. That's worth listening to, and rare. She's the real thing."

`Never Land' previews at the Royal Court at the Ambassadors, London WC2, from tomorrow (booking: 0171-565 5000)