"There have been many great idiots in sitcoms," says John Finnemore, "Manuel from Fawlty Towers, Alice in the Vicar of Dibley and Baldrick from Blackadder spring to mind. And there are many different types of idiot. I'm not sure I'd describe Arthur as a true idiot though. His defining characteristic is his utterly optimistic outlook and that he's resolutely cheerful."
Idiot or not, Finnemore is about to revive his character Arthur Shappey and it's the first time the eternal optimist finds himself on stage rather than his usual home on the wireless. The sitcom from which Arthur hails — Cabin Pressure — was a series about the crew of a tiny airline and broke all Radio 4's box office records; it attracted over 23,000 people to request tickets for its final recording. And while the main draw for many was of course Benedict Cumberbatch (who played the pilot Martin), the series kept all of the original high profile cast — including Roger Allam and Stephanie Cole — from series one in 2008 to the finale in 2014.
Arthur now flies solo with a specially written monologue at Shaw Theatre, where Finnemore will also showcase favourite sketches from his other hit Radio 4 sketch show, Souvenir Programme, alongside fresh material. Under the title Souvenir Cabin, the stage show gives Finnemore a chance to demonstrate different styles of writing.
"In writing long and short-form comedy; the main difference is long-form is much harder. With sketches the challenge is in terms of the number of ideas you might need.
"I'm working on the running order at the moment and we're intending to have different sketches for each night. It's basically a really daft decision because it means five times the writing and rehearsal."
The extra workload is due to Finnemore including different comedy partners from his Souvenir Programme, whom will take turns to join him each night. This has the consequence that each performance on stage will have distinct material than on another evening: "I think it'll be about two-thirds the same each night and they'll be one or two sketches that everyone will do but the rest unique to that performer.
Then, of course, there is Arthur: "Writing for the stage has been fun and I have to think more about how Arthur [who is normally unseen on radio] will act physically."
But, Arthur's sunny disposition is sure to be a winning presence: "Comedy characters are apt to be negative. They have a flaw that brings them down or into conflict. To have a character whose take is 'life is brilliant' offers a fresh angle. And, with Arthur it is so extreme it offers yet another comic lens."
John Finnemore's Souvenir Cabin will run at Shaw Theatre from 30 Sep-11 Oct (not 5), 7.30pm, £27.50-£37.50.