Tim Crouch's latest play, An Oak Tree, is performed by the author and one other actor, who is somebody different at each performance who must never have seen or even read the play before. This could so easily be just a gimmick - especially on the Fringe - but in Crouch's play this concept goes right to the heart of the play's meaning.
Crouch, when not playing himself, plays a stage hypnotist, and the actor is the father of a young girl that the hypnotist recently knocked down and killed accidentally. The actor never has to improvise his or her part; he or she is given lines and moves on pages of script or as directions given by Crouch - sometimes audibly and sometimes discreetly using a microphone and a pair of iPod headphones. Although there are a few long pauses for direction to be given, this all happens fairly smoothly and so the audience's attention is not allowed to wander.
This production is, however, much more than abstract performance art or an acting exercise. There is a great deal of humour in Crouch's performance as he banters with the audience and with his actor. The story deals with one person's struggle to deal with the death of his child and another's struggle to deal with having killed a child, despite having been found innocent of blame. It is also about identity and playing roles, as the father replaces his daughter with an oak tree, the hypnotist makes his volunteers believe they are somebody else and Crouch manipulates his actor into the role of the father.
Crouch and the actor slip between playing themselves and playing the characters, and any confusion over this is entirely deliberate - when we are not sure whether Crouch is instructing the actor or the hypnotist is manipulating his subject, this actually deepens the themes of the play. There are points when Crouch is telling the actor to relax and asking him how he feels, and even here the actor's responses are scripted and therefore entirely under Crouch's control. Even the audience is instructed in the role it should play during the scenes.
The actor deserves a mention even though no one else will ever see him play the role: his name is Sandy Grierson and he gave an extremely good performance. He gave a long speech about how he transformed the oak tree into his dead daughter in a very moving way, despite being prompted line-by-line by Crouch through his headphones.
This is a fascinating concept that has been realised in an entertaining and often very moving piece of theatre that will produce a very different performance each night.