So perhaps it is not so surprising to find the National Youth Theatre stealing a march on the RNT by staging the first major London revival of the show since Littlewood's mould-breaking original 1963 production.
According to NYT's director, Ed Wilson, Littlewood felt the show - a musical satire on the horrors and follies of the First World War - would be more likely to retain its essential rawness and honesty in the hands of the self-supporting NYT than with the subsidised might of the RNT. 'She is most anxious that the show isn't glitzified,' said Wilson.
Not much chance of that on the National Youth Theatre's budget of pounds 70,000, even bearing in mind that the cast of 20 does it for nothing. NYT is one of the few theatrical institutions in the country that straddles the great professional-amateur divide. All its administrators, artistic and otherwise, are unquestionably professional, while all its performers are technically amateur. The fact that its roll-call of past members includes Derek Jacobi, Timothy Dalton, Helen Mirren and Glenda Jackson bears witness to the high standards it sets itself. But the NYT does not see itself as a recruiting ground for the stage.
'The vast majority of people who have been through our doors have not gone into the theatre,' says Ed Wilson, himself a former NYT member who went on to become a successful actor. Another ex-member, Dean Byfield, who now runs an award-winning experimental theatre company called The Engine Room, is directing Oh What a Lovely War (right). Both he and the designer, Lotte Collett, are in their 20s.
'It's a very complex piece of theatre,' says Byfield, 'it's part documentary, part pacifist manifesto, part end-of-the pier show. If you force it in any one direction, you detract from the essence of the piece. There was an aura of untouchability about the show because it hadn't been done for so long, but the more our production has taken on its own identity, the less worried I've been about living up to the legend.'
'Oh What a Lovely War' is playing at the Bloomsbury Theatre, WC1 (071-388 8822) tomorrow to 10 Sept