THEATRE / The only way to keep a straight face: 'It is a play about erections,' says Peter Hall. Which is where the masks come in. Georgina Brown reports

'The trouble about masks is that as soon as you start talking about them, it's like luvvies personified, gone mad,' says Sir Peter Hall. Despite his appearance (director's standard issue - black, black and more black) and a tendency to darling his cast, Hall is among the least pretentious of theatre folk. But quote him on 'getting a mask to speak, laugh and cry', and even he sounds the teensiest bit precious.

Nothing, however, obcures his passion for masked theatre, which reached its apogee in his astonishingly daring all-male, full-masked production of The Oresteia at the National 12 years ago. Detractors found the masks guilty of masking the tragedy, making it difficult to hear Tony Harrison's thrillingly alliterative verse. Some trotted out the inevitable accusation that they denied the actors their most basic weapon - the face - and were only ever used by the Greeks because a. the occasion was a religious ritual, b. one actor played more than one role, and c. in the vast amphitheatres in which they were performed, the facial features needed to be exaggerated. Others said the audience's imaginations were limited by the fixed expressions and remained immune to the appalling suffering.

Hall wouldn't buy any of it then, and he won't now. 'Masks make Greek plays operate at a level of intensity that doesn't happen without them,' he says. 'In tragedy, the emotions are so huge and hysterical that the characters couldn't contain them without the mask; in comedy, it's the anarchy that needs containing.'

His latest project, Aristophanes' outrageously bawdy 2,500-year-old comedy Lysistrata, uses the comic half-mask, with the joke continuing through the costumes - the male, er, members of the cast don vast penises. It's an anarchic play with an anarchic proposition: when the women of Sparta (sexy, upbeat Greenham Commoners with a wicked sense of humour) trade sex for peace, the men's frustration becomes obscenely visible. 'This is a play about erections,' says Hall bluntly. 'It's about the pomposity of men, being frightfully macho and in control and yet this thing they can't control is arriving and going forth all the time. Without masks it would be too obscene - you couldn't do it.'

Hall believes that acting in a mask requires actors who are 'volatile in temperament, ready to go up and down and explore emotions. It's an exercise in honesty really. If it's not working you can see the actor you know underneath the mask and that's horrible, that's false.' The majority of the cast hadn't worked with masks before, so Hall went back to basics. 'You choose a mask which appeals to you instinctively,' he explains. 'You look at it, look at yourself and it in the mirror, and at that point you may decide that it has nothing to offer you. If it does, you look at it again until you feel ready to become part of it, then you put it on, lift your head and see the person in the mirror. You then become that person, you get a charge from it.'

That was a couple of weeks ago. It is still early days and rigid text work on Ranjit Bolt's gutsy, full-frontal adaptation in rhyming couplets is being kept separate from the maskwork. Hall and John Kane, an actor with whom Hall worked with masks in Stratford in the Sixties, have devised an exercise: three actors play clapperboard, sound and cameraman; the rest of the company take it in turns to audition for Casablanca in front of the show's assistant director, Edward Hall (Hall's 26-year-old son), the only one unmasked and permitted to speak English. Taking their cue from the caricature masks, the actors become grotesques, scampering around emitting maniacal shrieks.

Geraldine James's aquiline nose and chiselled cheekbones are invisible beneath the brown, bulbous features of an old woman. A few gold hairs spew through the eye sockets, adding to the hideousness. As soundperson, she capers like a demented ape. You wouldn't have recognised her in a million years. Diane Bull lurks somewhere behind a moustachioed spiv, a black hat and umbrella. Another actor, sun-glasses perched on an extended orange beak, his trousers rudely grabbing his crotch, tears around jabbering like an over-excited village idiot.

'That's the masks working - they are like children of three or four - disobedient, gross,' says Hall. The energy the masks unleash is alarming, nightmarish and hilarious. All of a sudden, The Beak grabbed a bicycle and vanished out of the rehearsal room doors and down the street. Minutes later a policeman in a Sierra waved him down and asked if his brakes worked. 'Very Aristophanic,' laughs Peter Hall, restoring order to the proceedings.

'In the Oresteia it took two months before the masks would say anything really coherent. We are at that stage here in that these people aren't prepared to act like rational human beings. The anarchy is very valuable - we need it, but in this state they'll never speak the verse. Two actors withdrew from the Oresteia with nervous breakdowns - the problem wasn't being hidden, it was being released and confronting the violence in themselves. There are the same dangers with a comic mask - you can't stop the puppets. Actors wearing masks need to grow up gradually. You don't play a scene with someone in a mask by fixing your eyes on them as in a naturalistic play. You look at the person, turn and look at the audience, then look again - it's the double-take - Morecambe and Wise, to do with playing an audience.'

When Diane Bull, a superb comedienne, accepted the part, her agent said: 'It's in a mask, darling, do you still want to do it?' 'I did. What's surprising is that you think you can hide behind it, but you feel freer and able to be quite wild.' Music to her director's ears. According to Geraldine James, who plays the title role: 'When you've conquered it, it's like conquering Shakespearian verse - very hard but extremely liberating. I have to find another way of showing my surprise - not raising my eyebrows, but bending my neck and holding my head in a different way. The extraordinary thing is that the play isn't like a circus; it's so truthful about why men don't listen to women, it feels like Screen Two.'

Hall, too, compares wearing a mask to the demands of Shakespeare's verse and, indeed, to Pinter's rhythms and pauses, and to a Mozart aria, restrictions which are paradoxically liberating. 'They are artificialities which represent realism but aren't realistic in themselves. All great theatre writing is close to the mask. There's a form you have to accept, and by accepting it, you release yourself.'

In this play, though, the masks will perform a vital additional function. It's the only way the actors will be able to keep a straight face.

'Lysistrata' is at the Old Vic (071- 928 7616) from 9 June; opens 13 June.

(Photograph omitted)