This enduring Radio 4 show is one of those excellent ideas that seems glaringly obvious once someone else has thought of it. The basic concept is a hostless chat show; an initial guest chooses a sparring partner who, the following week, chooses another, and so it goes on in a cheerful human centipede of chat. This series began with Adam Buxton talking to Reece Shearsmith and has passed through a range of comedy luminaries, including Vic Reeves and Sharon Horgan.

In praise of Chain Reaction

Chain Reaction; an ingenious little show that's been bubbling away on radio's equivalent of People's Friend magazine for years.

The idea behind Chain Reaction, if you haven't listened (why?), is that last week's interviewee becomes next week's interviewer, so we get a long list of famous people (usually comedians or actors) interviewed by a similar person who they admire or have worked with. Each person's interview technique is very different, so the show is hit and miss. The last two week's programmes, which featured Bob Mortimer interviewing Vic Reeves, and then Vic Reeves talking to Olivia Colman, have been tricky listens. I love Reeves and Mortimer but they don't do interviews, really. When they were together it was funny but utterly random; when Reeves talked to Colman, I had to switch off. He had no questions; he didn't really listen to the answers. Argh! It was frustrating.

This week, Colman talked to Sharon Horgan, and I enjoyed the whole show. Colman managed to take the mickey out of the interviewing process ("Do you have a favourite sibling? Do you have a favourite child?") and also get revealing answers. Revealing of both Horgan and herself, which made up a bit for the week before. So we learned that Colman can't cope with too much to do (and then her husband points out that what she's worrying about could be done in a hour), that Horgan prefers writing to acting, and that despite being born in England she considers herself Irish - "it's very important to me that I'm Irish". The chat brought out the contrast between Horgan's career-minded pragmatism and Colman's family-comes-first attitude. As well as both women's wit. Colman was a great host. Give her a show. Nurture the "talent". Manage it.

Radio Times review

"Do you have a legal list?" Olivia Colman asks her interviewee Sharon Horgan. "Sorry, what's that?" responds Horgan, in answer to which Colman informs her it is a list of people you are allowed to sleep with without your husband getting cross. The audience roars with laughter, which soon increases in volume when an innocent Sharon asks, "Can they be dead?" -- not quite making the necrophilic link implied by her wish to have Steve McQueen on her "legal list".

This gives a flavour of the conversation between these two very funny women. Colman's questions cover topics ranging from work--life balance to the joys of nit-combing a child's hair, and Horgan's wickedly witty responses exemplify why she is at the top of her game at the moment.

Radio Times review

Graham Norton, Jonathan Ross and Alan Carr are not going to lose any sleep if they listen to this. Jim Moir, better known as Vic Reeves, is not a natural interviewer. It's his guest, Olivia Colman, who holds the show together, using her ability to ad-lib with wit.

I love this series. I love Vic Reeves. I love Olivia Colman. It's why I chose this as my Pick of the Week. But were it not for Colman's thespian talents there are moments when tumbleweed would have blown through the studio (à la Shooting Stars). She picks up when Reeve's questions or direction of thought trails off, and yet, while he sounds delighted to have got to the end of the show intact, there are some parts where this interview is so funny it should come with its own health warning.

If Olivia Colman had to choose between a plastic hand and a hook, which would she favour? Is she any good with blood? As I said, Reeves is not your typical interviewer, but these surreal questions do encourage Colman to reveal more about herself than she would on a predictable chat show.

And so, I now know that she believes that the path to true love depends upon clutching a fallen eyelash with one's intended and making a wish. And that she can spend hours staring at pictures of men's swollen testicles (in medical books, not real life).

It's a peculiar half-hour, but one I wouldn't have missed for the world.

Radio Times review

Bob Mortimer may well be in trouble with his wife after this broadcast. He has told her that he works from 9.30am to 4pm with his comedy cohort Jim Moir (Vic Reeves). He now confesses to Reece Shearsmith that they stop feeling funny around 2pm and he has a nap in a car park.

Such endearing revelations are all part of this show's appeal -- it gets great stories because the interviewees feel comfortable enough to share.

The driverless car of chat shows, Chain Reaction (BBC Radio 4), returned this week with Adam Buxton firing questions at The League of Gentlemen's Reece Shearsmith. The tag-team format allows for a nice variation in tone (the host baton passes to Shearsmith next week, with a new guest in the other chair), but when the host is as thoughtful and considered as Buxton I almost wish it was his show alone. He's the ideal blend of gentle irreverence and a genuine interest in other people. For all the novelty of the format, it was a good, old-fashioned interview, with Shearsmith offering up everything from impersonations of his old acting teacher and revelations about his childhood (he was nearly christened John Wayne) to the intriguing story of the time he became the apprentice to special-effects artist Christopher Tucker, only to run away from his house in the middle of the night "like Jonathan Harker fleeing Castle Dracula". In a brilliant summation of his comedy oeuvre, including The League of Gentlemen, Psychoville and Inside No. 9, he describes the template as: "Three people in a room. One of them goes mad." Chain Reaction is such an obvious candidate for translation to television that it's puzzling it has yet to make the jump.

Radio Times review

Reece Shearsmith looks rather dour as he explains to his interviewer, Adam Buxton, that his looks have helped cast him as the villain/psychopath/character-most-likely-to-run-amok in the sketches of The League of Gentlemen. Is he angry in real life asks Buxton? Not really, he says. If anything, he thinks he has gone soft in his middling years.

He confesses to looking back at a sketch where a vulnerable character is bullied by teenage girls and thinking that he'd crossed the line, that the cruelty had outweighed the laughs. Push him a little harder though and he is soon chuckling over the Sardines episode of last year's Inside No. 9, which he co-wrote with fellow Gentleman, Steve Pemberton. Inspired by a cupboard in the office they share it involves 12 bodies squashed together -- and some child abuse. It does not sound funny but, as Shearsmith points out, it's the dark drama that has made his comedy so different.

Next week he gets to be the interviewer and Bob Mortimer answers the questions.

When I spoke to Carl Cooper, the producer of this series, I asked how much of the material for this edition - Kevin Bridges interviews fellow Glaswegian comedian Frankie Boyle - had to hit the cutting room floor. "It was a tricky one, content wise," he conceded, but you'd never know it from this brilliant edit.

All right, you might have an inkling when Boyle starts talking about beaming porn onto the outer walls of primary schools - not a practice he supports, takes part in or suggests, I should add, before the green biros come out to start an "appalled from . . ." letter.

For the most part, the conversation is on why the controversial performer has decided to stop - spending time with his family became more appealing than being under constant scrutiny for every word he said or wrote. There's an interesting section on why Boyle hates comedy panel shows where he reveals how scripted and planned they are, and how much he liked to drop a grenade into such proceedings.

He's certainly not lost his precocious comedy gift and shows like this are evidence that he can be put before a microphone without bringing a broadcast company into disrepute. I'd like to go on record now that he should be a guest editor on The Today Programme next year.

Chris Addison will be pleased with this picture - there is very little bare flesh on show and certainly nothing suggestive of his nether regions. In a terribly British section of his interview by friend and fellow comic thespian Rebecca Front, they discover a shared aversion to nudity, especially their own, in performances.

As Addison remarks, his modesty is based upon his body resembling a stick man made out of Twiglets. Their similarities do not end here, however: both confess to having been goody-two-shoes at school and how many other modern comedians can claim to have been part of madrigal groups? Middle-class and brainy does not have to mean smug, though, and so this interview rubs along nicely. I look forward to Addison asking the questions of Derren Brown next week.