Here’s another one…5.24pm: Thirty-six minutes to go, and the theatre is filled with busy expectancy.On the mezzanine above the entrance to the theatre, Chris and Harriet have laid out great piles of paints, charcoals, chalks, crayons, pencils alongside four large white boards – blank terrain for the ‘The Great Mass Improvised Draw’ over the next 24 hours. The Factory – the people who are going to be performing their improvised Hamlet and The Seagull over the next couple of days – arrived mid-afternoon. They’ve done their rehearsal – or, rather, as one of them described it to me, their training session. Now they’re eating. At 6pm, they’ll be performing their Hamlet. They don’t know yet who is going to perform which part, or what props they’ll be using, or where they’ll be in the building. (Though I think they’re scheduled to start in the Studio space…)Amusing encounter between Federday, member of the Factory company, and her friend Simon Godwin, also a friend of mine and associate director here at Bristol Old Vic.Federay: When are you coming to see our Hamlet?Simon: I’ve already seen it.Federay: So?AAARRRGGGHH!! Simon realises that his obligation to see this play – in this production at any rate – is potentially endless.To be a real friend to this show, you need to see every single performance.As a writer, I’ve had the – relatively unusual – experience of seeing a show repeatedly (my own), and becoming fascinated by how much the performances flex – in response to the audience, the actor’s mood, and other, untraceable influences.What relationship does this, the ‘ordinary’ unpredictability of any kind of live performance bear to the unpredictability of an improvisation? Do we like improvisation because live theatre is not live enough?I’ve also realised that I should try and see one or two things more than once…(To see if they’re really improvised, another one of the Bristol Jam team jokes to me later. Imagine the horror if I discovered that two performances were the same.)7.12pm: The Jam has begun. The white boards are already half-filled with a baroque tangle of drawings: a manga heroine, a stage with attentive audience, a flying saucer, a woman reclining in a swirl of flowers, crosses masked out of smudges of charcoal. People are meeting and talking as they draw alongside each other.Members of the youth theatre are walking around in character offering us the opportunity to commission individual improvisations. Hamlet is underway – somewhere in the building.I’ve just been to see the Scots Falsetto Sock Puppet Theatre, which was hilarious. We’re going to do something we’ve never done before, said Sock Number One. Isn’t that what improvisation is, asked Sock Number Two?