Toby Jones, Frances McDormand and Mike Myers are some of those who have appeared alongside Tim Crouch in An Oak Tree, despite never having seen the script before. As the play celebrates its 20th anniversary, past performers explain its strange appealThe standard routine in theatre goes something like this: an actor is cast in a play; they read, learn and rehearse it; and then, at last, they perform it to an audience, who will hopefully soak up their hard work. But for Tim Crouch, one of the industry’s chief experimenters, this exercise began to feel reductive. “A lot of actor training is about holding focus within the stage and putting the audience into a receiving role,” says Crouch. “I used to go to pubs and bitch about it.”An Oak Tree – his 2005 play that is now seen as a landmark work – was born directly from these frustrations. The script, which is written to be performed by Crouch and a new actor each night, celebrates its changeability. “It is a finished p...