Like the National's Nicholas Hytner, Broadway's Jack O'Brien is also an artistic director, but unlike Hytner, is far from new to the job. He's been running the Old Globe Theatre in San Diego for the last 22 years now. But he's also had a hugely productive parallel career as a freelance director, where his credits have recently included directing this season's most successful new musical on Broadway, Hairspray, and have previously seen his Broadway productions of Damn Yankees and The Full Monty both transfer to the West End.

The two worlds O'Brien exists in have now collided - in the first show he's ever been asked to originate in Britain - at the National Theatre, at the invitation of Hytner. The American first encountered Hytner wearing his other hat. He recalls: "For the last eight or ten years that I've known him, I've been trying to get him to come to the Globe to direct. Once a year I call and ask him, and he says, 'I can't'. I'm very sweet about it - I'm not jealous and manipulative, but I simply call again next year. But now that he's taken over the National, he called me, and said the boot is now on the other foot, and asked me to direct here! And I thought it was delicious, and accepted!"

Badinage & madding crowds

The play O'Brien's directing is a world premiere stage adaptation of a film classic that is itself based on a play - Ben Hecht and Charles MacArthur's The Front Page, as gender-transposed into the movie His Girl Friday. "The film pushed the original play down the pike to allow for the first 22 or 24 minutes of badinage between Rosalind Russell and Cary Grant that doesn't exist in the play," says O'brien, adding "the idea to put His Girl Friday on the stage has been in the air before, but the exigencies of the amount of people who have to get into bed before you can do that is daunting, to say the least."

The director's referring now not to getting Russell and Grant's characters into bed - though the play does put the sex into the story - but to the rights issues, partly resolved by doing it here in Britain. "We're far enough away from that madding crowd that it allows everyone on the American end not to panic!" O'brien expands. "And then who wouldn't be wildly flattered by an offer from the National Theatre of Great Britain? It's a safe house and a distinguished commodity, so at least they know that the dish won't run away with the spoon!" O'Brien, who has an apt way with a phrase, goes on: "It all made it a perfect moment in time for the tumblers to fall together to make this happen".

And making it happen according to the constraints of the Travelex £10 season - in which scenic resources are limited so that two-thirds of the Olivier seats can afford to be priced at just a tenner - has meant "that we've had to go back to the original play and do it on one set. We couldn't have two scenarios, so we've had to go back to the idea of the original play and then weave that structure into this. Into a lot of that goes a lot of John Guare (the American playwright who's adapted the piece). In order to solve some of the problems, and get people onstage where they need to be, he's had to invent other things, and then, in order to facilitate farce, I've had to invent a lot of stuff, too - so it's a brand-new show!"

A whole new ballgame

But why not simply do The Front Page? "It's done frequently, and I'm not sure we are all necessarily aching to see a new production of it, even though it's built like a Buick and it always works. But this piece - to get the sex into it - is a whole new ballgame, and it's worth sitting up and taking notice."

As a director, O'Brien is an instinctive problem solver, which makes him ideal for developing new work. But in a long career, he has been equally adept at old plays, too. "One of the jobs you have as an artistic director is picking up the ball, so you get to exercise on all areas of the spectrum. Somebody is forever getting sick or getting another job and not coming, so you pick up the piece, whatever it is, and you do it. Over the years, like lifting the calf in the barnyard, you get good at it, I guess."

He's definitely good at it; and when pressed to articulate his strengths as a director, comments: "It's hard for one to know that - other people might tell you - but I begin to understand that my work seems to have an emotional cohesion that people recognise, that they are somehow emotionally involved in the journey. Even if it's a hilarious journey, they believe in the people. That's become something I try to invest in all my work. Also, I'm hilariously funny - he says modestly! But I am - I'm also bald; both of these things are a reality!"

Healing, faith & ritual

O'Brien is also nothing if not fearlessly honest. In a previous interview in the New York Times, he spoke movingly of how the death of his long-term partner affected him, and how he plunged himself back into his work. Talking to now, he says, "What are the alternatives? You fall down and say my life is over, or you say, 'I just sustained this extraordinary loss, but I'm not the only person ever to go through this'. There are options. And there were open to me these magnificent opportunities and a great deal of love and support and work from people who cared about me, and projects that I really did understand - so I poured a lot of my feelings into all of the work, and what I've done just changed from that time substantially.

"I didn't want to turn my relationship into a dark place. I didn't want it to be the end of something, but to work hard instead to make it represent a celebration of something. I don't see a better way of working through grief than by working with wonderful, loving people in a great situation. Theatre is a healing place and a place of faith and ritual - that's one of the miraculous things about it."

It's also, O'Brien says later, "one of the miracles of life to sit in an audience of total strangers, and have them go off at the crack of a rifle every night at exactly the same moment because of a piece of exquisite staging you've done. Comedy that elicits an actual response from the audience is something that's not subjective - it's out there, and it's miraculous. You can't fake it - it either works or it doesn't."

In O'Brien's case, it works far more often than it doesn't.