Hours before the opening performance of Bacchai, Sir Peter Hall sits alone in the stalls of the National Theatre, appearing more like an overeager theatregoer than celebrated director. With the production now fully polished and several tedious hours to go before the performance, he is not averse to distractions. "I feel like the spare prick at a wedding," he says while waiting for the other half of the collaboration, Sir Harrison Birtwistle. The conversation eventually strays to the origins of their long artistic partnership when, on cue, the composer enters.
It has been more than 20 years since they last collaborated at the South Bank. After such a long hiatus, it is tempting to assume that the timely eloquence of Euripides's Bacchai - about a charismatic religious leader and his followers from the east who seek to destroy the west - prompted them to renew their affiliation. Not so. The decision was made more than two years ago, and by a much less catastrophic event. "Harry wrote me a postcard saying isn't it time we do another Greek play," says Hall.
Their personalities are remarkably complementary: Birtwistle gnomic and introvert; Hall articulate (if not well-rehearsed) and extrovert. Each now moves with the gravitas of an old master, and over the years both have ossified from modernist enfants terribles to establishment monoliths. Bearded and stout, both are dressed for the evening performance in dark suits, yet still appear hopelessly ruffled. The two knights are unmistakably kindred spirits.
Hall first heard Birtwistle's opera Punch and Judy at a "terrible, grotty little theatre" in London, and left impressed enough to invite the composer to be the musical director of the National Theatre in 1975. Their partnership yielded a string of celebrated productions: Amadeus, Volpone, the late Shakespeare plays, and, perhaps most significantly, The Oresteia in 1981. The latter was particularly significant because Greek myth has been a constant presence throughout the careers of both men, and provided much of the thrust to their collaborative efforts.
The question of why anyone should rehash Greek drama often arises but shouldn't, says Hall, especially when considering the disturbingly contemporary themes of the current production. "Bacchai has been on my list of essential plays. It's about east v west, atheism v faith, male v female, law v freedom. It deals with the impact of repressed emotion over instinct. It's always timely."
The director and composer first began to develop a modern language for Greek drama while working on The Oresteia. Hall says: "It was when this theatre had The Oresteia and Guys and Dolls on the repertoire. A proud moment. And, actually, some of the cast were in both."
They have enjoyed a rare luxury at the National, which has allowed them the time and resources to experiment. "I don't know another theatre which would have given us ten weeks of rehearsal and the musicians. I think that that is what the National Theatre is for," says Hall. Birtwistle, hinting somewhat obliquely to criticisms of the NT's cultural levelling in exchange for government subsidy, adds: "I got very depressed about what they did here." But the resources have undeniably served them well.
They have managed a difficult trick with Bacchai. By remaining true to the rigid formal devices of Greek drama, they have created a production that is at the same time convincingly ancient and modern. Only three masked actors perform the principal roles in the play. The masks serve as a "magnifying glass of the text", says Hall, "used as an instrument of concentration to help understand the words. You can tell the audience what the text is rather than muttering it to each other, hoping they will understand."
The writhing, androgynous chorus of masked male and female actors not only provides the middle ground of Bacchai's polar extremes, but poignantly captures the deviance wrought by the repressive ruler's denial of the debauched god. "The chorus is not the same as the chorus in the Handelian sense," says Birtwistle. "It is actually full of information, whereas in the chorus of an opera they say very few words, and keep repeating them." Hall agrees: "They're not just singing 'Joy' or 'Hallelujah' over and over again. They are actually like the subconscious, an emotional reaction."
Other than a new translation by Colin Teevan, there were no preconceptions going into rehearsals, and by fully collaborating on most aspects of the presentation, they have forged a completely integrated work. "We didn't know what we were going to do," says Hall. "It was all done in public, with the cast, musicians and everybody."
"You see, what I've done with it," says Birtwistle, "is that I have a secret bag of rules, and so it's all in fact very thematically linked. I can just put something in as long as the timing is right."
The production has one foot in the more nebulous realm of music theatre. "It's very much like the way Monteverdi created opera. I can imagine a way of taking the whole thing a step further into music," says Hall, and laughs. "I said to Harry yesterday that he should take it away and write over an opera."
When asked about the next collaboration, Hall and Birtwistle look wistful. After a long pause, the composer says: "I hope so." Hall adds: "Well, that would be nice . . . yeah. There are certain relationships in one's life that you can pick up, and go on again."
Bacchai is at the National Theatre, London SE1 (020 7452 3000), until 12 June
