Where do creative ideas come from? A friend of mine thinks his beard receives them from the ether, and that when it grows too long the drooping hairs become less effective aerials. He is a wrong and lazy man. Most successful shows and stories evolve in the secrecy of writers’ garrets or rehearsal rooms before
being inflicted fully formed on a public who have played no part in their creation.

But what opportunities are there to involve an audience in the process of probing and retreating that leads to a finished work? Ten years ago I remember, through rose-tinted vapour, we’d fill a sack with hats, cobble together the kind of confused comedy show we couldn’t do in a mainstream venue, take it to the Edinburgh Fringe, revise it daily, lose a grand and learn something. But today the Fringe is a market-place, where TV executives gauge festival audiences to guide their cheque books. The communal arts workshop has become a commercial showcase, costs for performers have increased accordingly, and correspondingly higher ticket prices mean audiences now expect to see a piece of work, rather than a work in pieces. One fringe comedy newcomer lost £17,000 on his first ever Edinburgh run this year. The Festival is no longer somewhere I personally could afford to experiment, and even hiring a London fringe venue could cost £500 a week.

But was there a magic place midway between my bedroom where I write down ideas at night with no risk of ruin and the certain debts and possible public humiliation of the Scottish front? It appeared there was. It was the Battersea Arts Centre in South London, quietly sowing little acorns in its “Scratch” performances.

The BAC’s child-faced director Tom Morris likes nothing more than to be continually referred to as TV satirist Chris Morris’s younger brother whenever he is mentioned in the press. As if in pursuit of his own distinctive identity, he first began presenting works-in-progress in 1998, with a piece by The Full Monty’s Emily Woof, which subsequently transferred to the Purcell Room.

Morris presents the BAC’s “Scratch” ethos as a way for writers and performers to develop unfinished ideas in an environment where both expense and audience expectations are refreshingly minimal. Artists try to learn from the punters, rather than try to impress them. Introducing a work-in-progress by theatre duo Ralph Ralph he explained to the crowd, “They’re not sure what the story is yet, so if you see anything resembling a story, find them at the bar afterwards and tell them.” The idea seems to be working and some of the seeds sown in last year’s Scratch season are already ripening into swollen, juice-filled fruits.

Last summer I directed and contributed to the libretto of Richard Thomas’s still not quite finished Jerry Springer ­ The Opera, where a cast of 14 portrayed the trailer-trash nightmare in song in BAC’s main house to a rapturous reception.

But only months earlier Thomas had performed a show called How to Write an Opera About Jerry Springer under the sheltering Scratch umbrella. Here he sat alone at the piano and asked the audience to imagine how such an event might sound, while offering free cans of cheap lager to anyone offering useful suggestions. Typically, some die-hard fans have since claimed, erroneously, to prefer this now legendary show to the later product, but there is something to be said for the thrill of seeing an unfinished work gestate. Personally, I liked it best before Richard had even thought of doing it, and when he himself was just an embryo, floating blissfully in his mother’s womb ­ though back then the composer’s potential appeal to a wider audience was admittedly limited.

This month, alongside Point Blank’s Nothing to Declare and The Jammy Tarts’ Christmas Special, my own-work-in-progress, Pea Green Boat ­ inspired by an ignorant misinterpretation of Edward Lear’s The Owl and the Pussycat ­ is a recipient of the Scratch unction. At the time of writing, just over a week before its four-day run, it comprises 20 minutes of the Owl’s diary entries, six slides of owls, an RNLI tea towel, and four plastic bags of false excrement.

A nervous cello player is being pressurised to perform and the comedian Simon Munnery, who has quite a long beard at the moment and thus looks a bit like Lear, today agreed to appear in the show. There will not be time to rehearse any lines for him but he has a fascinating aspect nevertheless.

This lack of preparation is no vainglorious boast. I am not proud. I wanted a chance to try out things I couldn’t do in comedy clubs or theatres. I wanted to see how far away I could get from the structures I’ve used as a stand-up while doing what is still a show in which I come on and say some funny things.
And I wanted to force my hand to begin playing with a bunch of ideas I hope will form the basis of my second novel. The Battersea Art Centre’s Scratch ethos has provided the kind of open-ended environment that makes this possible.

I hope I’ll do the show again, but Scratch also allows me the opportunity to abandon the idea before it’s too late to stop. Maybe Pea Green Boat will become a huge West End smash with dancing owls and ice-skating cats, disliked only by people who saw it when it was just slides, a confused man with a beard, and me speaking.

“It was better when it was raw and real and honest,” they will say, obviously. Either way, tickets cost less than a packet of cigarettes, I’m contractually obliged to invite feedback from theatregoers in the bar afterwards, and if only one person comes and pays £3.50 I will make more money than I have in 14 years of Edinburgh Festivals put together. Scratch it and see.

‘Pea Green Boat’: BAC, London SW11 (020 7223 2223), Thursday to 23 December;
‘Jerry Springer – The Opera’: BAC, 5-23 February, 2002