There are two ways to discover what acting naturally is all about. Either watch Edward Petherbridge (right) discreetly walk away with The Seagull at the National in the inauspicious role of Dr Dorn, or catch his one-man show.

Is Acting Naturally just another party-piece writ large? 'I find it much easier to describe what it's not. It's not just a show-off piece although I do show off some of what I can do. I've never written it down and it isn't a lecture, but I do ask questions and analyse on the wing. I just delve into my fascination with theatre, and people love peeping behind the scenes. As an actor, one always has to keep the theorist and commentator at bay. This is an opportunity for me to theorise a little . . . and throw in healthy amounts of puncturing self-deprecation.'

Acting is usually about giving the impression of extemporising, doing it for the first time. 'With this, the reverse is true. I stand there making everyone think how terribly wrought and well thought-out it all is.'

Together with his enviable ability to reduce rooms to tears of laughter with an inexhaustible fund of stories, he ends up with a whistle-stop tour of theatre, encompassing masks, a piece of scenery designed by Edward Gordon Craig and stand-up comedy. He has also just discovered that there's a piano on the Greenwich set. 'Perhaps I'll even throw in my show-stopper from Valentine's Day . . .'

'Acting Naturally' is at Greenwich Theatre on Sun 21 Aug and Sun 4 Sept (081-858 7755)

(Photograph omitted)