The antidote to all stage shows

Scanning BBC radio listening figures, I'm Sorry I Haven't A Clue shows up as an effortless and hugely successful survivor after 35 bewildering years on air. It is a fixture in the Radio 4 schedules, attracting a listening audience in the hundreds of thousands for each episode, and pulling in vast crowds at venues for recordings wherever Messrs Humphrey Lyttelton, Barry Cryer, Tim Brooke-Taylor, Graeme Garden (plus a guest, and, of course, scorer Samantha) choose to appear. But what's this? The team (combined age 286) has embarked on a short tour of stage shows that will not be recorded, let alone broadcast - just performances allowing the old lags to do their greatest - and filthiest - hits before paying audiences.

This tour, which reaches the New Theatre in Oxford next week, nearly never happened. Unbelievably, the BBC, while agreeing to the concept of the live act, decreed that it should not carry the programme's name. There is Corporation baggage in such matters: a few years ago, BBC Publications passed on bringing out what turned out to be a hugely successful book from the Clue franchise. Luckily, as Barry Cryer told me: "I was hardly looking for a career move, but I mentioned this to a journalist and said we can't use the title.

"And then it appeared in all sorts of papers and I rang our producer, Jon Naismith, and said: 'Have I rocked the boat?' and he said: 'Yes, and quite right too!'" The BBC backed down.

Which is why the lads are barnstorming around the country berating audiences with rounds such as One Song to the Tune of Another, Sound Charades, Uxbridge English Dictionary and the great Mornington Crescent (look, if you don't know what I am talking about, treat this merely as an antidote to previews!). Jon, who took over producing the radio show in 1992, has overseen this commercial transformation for the stage.

"It's a sort of the best of the past 35 years," said Jon. "We're packing in ten or so rounds, all tried and tested favourites. Will it end up dirtier than the radio shows? Maybe a little, but we're not out to alienate the audience. It might be difficult to control Jeremy guest Jeremy Hardy, but this has always been a problem."

Clue's huge success is, says 72-year-old Barry, down to two people: "Humph is the patriarch - endlessly courteous, but actually saying to himself 'I'm bored and I want to go home'. He is a great admirer of Kenneth Horne and there's a lineage there: Horne in Round The Horne was the urbane man in the middle of idiots." And the other? "Graeme Garden, who effectively invented the concept of the programme. He's the most inventive; he's always good news and his brain is always running full time."

Cryer met Lyttelton decades before Clue was invented, and clearly still reveres him: "We met at Leeds University when I was singing with the University Jazz Band, and the great Humph was 34 and already a star and came to perform at the university in, I think, 1955. Right, now, I'll give you an honest answer, not a diplomatic one: it's him, he's the focus for the whole show. "He's the absolute hub of the operation. When he's doing references to Lionel Blair or Samantha, I don't look at him. I look at the audience, and then he does this amazing double-entendre which you simply can't believe. And there are nice women wiping their eyes with mirth because it's him, his persona."

Those links are written for Humphrey Lytellton on radio and for the stage show by Iain Pattinson, brought on to the show in 1992. A veteran writer for two other major Radio 4 shows (The News Quiz and the Ned Sherrin opening monologue for Loose Ends), I asked him whether he went over the apparently dubious material in his script in advance with the producer, especially given that Humph does not see the script until just before the performance.

"There is no filth in the script," said Iain. "Any smutty misunderstanding is all in the mind of the listener. When I get letters of complaint from listeners, I thank the Lord there are people like them with such dirty minds that they can explain to me what I've done."

He then gave me what I thought was a brief masterclass in how exactly his writing process works.

"All jokes for the show should be timed in the writing. To allow the audience to compute the resolve, you have to put in the right amount of timed - on and off beat - pad, between the set-up, the feed, the mislead, the reverse and the breath - before the half-reveal, the reveal, the tag and the topper."

And before you ask: no, I've no idea what any of that means. So let's just get our seven-inchers out!

For the record, I obviously asked Barry Cryer both about scorer Samantha and the rules of Mornington Crescent. He was happily open on both vital matters. "Sam is 29 and gorgeous. It's very disturbing for people of a certain age." MC? "It has a base and it's club rules and it's understood between us all. If I tell you more, the game's up. It's to do with words, not just the tube stations, and that's all I'm saying about it."

Clearly, much thought and planning has gone into this stage version of the radio favourite.

Was Iain Pattinson going to be present at all the shows, adapting and learning from what may or may not work in the different format? His reply was as deeply creative as one might have expected from anyone concerned with this comedic classic.

"I won't be at the shows, taking notes and improving the script. We've found over the years that a mixture of contempt for the audience and complete complacency over the repetition of tired material is a winning combination."

I'm Sorry I Haven't A Clue takes to the stage of the New Theatre on Tuesday. For tickets call 0870 606 35000.