Now, though, it seems, radio has begun refurbishing itself as a retirement home for senior television shows. To the Manor Born, nominated as one of the BBC's best television comedies at its recent 60th anniversary awards, has been granted a new lease of life by Radio 2. No matter that the vehicle for Penelope Keith made its last appearance on television 16 years ago. Rumpole of the Bailey, equally long in the tooth, also returns this week in the form of a radio reading by - who else? - TV's long-running Rumpole, Leo McKern. Programmes don't have to be pushing up the roots of the daisies to catch radio's eye: also coming up is the audio version of As Time Goes By, another sitcom about middle-aged sexual tension starring Judi Dench and Geoffrey Palmer. Even as 13 old editions are being recycled for radio, the sixth series is currently being made for television. Nor do they have to be the BBC's baby: Shelley, one of the few fondly remembered sitcoms from ITV, is also on Radio 2's shopping list.
If you've been looking for an example of bi-mediality that doesn't involve Brian Hanrahan cropping up on PM, you can call off the search. As well as developing its own playhouse comedies, some of which may one day transfer to the small screen, Radio 2 is actively trawling the television archives for cheap, pre-fabricated ideas. Bi-mediality is just Birtspeak for licensed poaching. These old television shows may have been crowded out of an overheated marketplace, but radio is more than willing to take them in.
There are two separate broadcasting trends that overlap here, neither of them especially welcome. The first involves the blurring of the distinction between radio and television (a basic principal behind Birt's restructuring of the BBC): the free trade in ideas can only erode the differences between them, to the inevitable detriment of radio's individual voice. The second involves the tentacular reach of the nostalgia industry. The growth market in archive entertainments, which brought you the radio stations Capital Gold and Virgin 1215 and the satellite channel UK Gold, is now creating a kind of Radio 2 Gold. Rather than conceiving programmes for which listeners will one day grow nostalgic, Radio 2 is simply adopting TV nostalgia readymade.
It would be misleading to claim that the path from television to radio has never been trodden by comedy or drama. In the 1970s, Dad's Army led a double life on BBC1 and Radio 2. More recently, Radio 4 cunningly disguised Victoria Wood: As Seen on TV as As Heard on Radio. And last year, The Darling Buds of May made a valedictory appearance on Radio 4 in an adaptation of the last of HE Bates's Larkin stories (which television - ever radio's more squeamish younger sibling - had rejected because it ends with Pop Larkin's death).
But whereas it once looked like a coincidence, now the radiophonic resuscitation of moribund TV shows has become policy. "We know that television repeats programmes," says Jim Moir, the controller of Radio 2 and the former head of light entertainment at BBC TV, who is directing the traffic of comedy back towards the wireless, "and often getting bigger audiences than the first transmission. They clearly have an afterlife. It's foolish to think that because they have been on television everybody has seen or heard of them." The parallel lives of As Time Goes By would suggest that listeners and viewers are two entirely separate species, but To the Manor Born can only be relocating to radio precisely because people have already seen it. As the bizarrely lucrative market in audio cassette versions of highly visual TV shows like Blackadder and Not the Nine O' Clock News surely proves, audiences accept sound-only mementoes precisely because they already carry the images in their heads. "This sounds rather pompous," says Penelope Keith, "but so many saw the show, I should think a high percentage of people listening in will have seen it. And a great help to us as performers is the fact that they know the characters. It's a sort of deja heard thing."
The first rule of nostalgia being that the fondly recalled always remain just the way you remember them, radio actually offers some in-built advantages for any sitcom that has reached the menopause. The recent TV revival of The Liver Birds signally failed to clear the awkward hurdle that its chief characters had aged with the actors who played them. On radio, though, wrinkles are not an issue. Penelope Keith, who, on screen, is nowadays reduced to playing a grandmother in Next of Kin, can lop off 20 years on the wireless, while major cast changes, such as that by which Keith Barron has transplanted Peter Bowles as the arriviste tycoon in To the Manor Born, can be discreetly accommodated. Really ghastly TV shows can even be given a complete facelift, as with Shelley, which will be entirely recast for radio. There is, however, one effect of ageing that even radio's reconstructive surgery cannot remedy: Reggie Perrin may have feigned death, but Leonard Rossiter sadly wasn't faking, and TV's recent sequel, The Legacy of Reginald Perrin, had to stumble on without its star. (It was because of Paul Eddington's death that Penelope Keith flatly vetoed Jim Moir's proposal to revisit The Good Life: "It was so associated with the four of us, and one couldn't ever think of doing it with anybody else.")
Though few of these shows ever receive their kiss of life from radio without first having been pronounced dead by television, there can be advantages in seeking a second opinion. Probably the most seamless transfer from television to radio was achieved by Resnick, the sequence of Nottingham- based crime novels written by John Harvey, who has also written profusely for both broadcast media. Two Resnick stories were filmed for BBC1; then, when it became obvious that television would not commission any more, two further adaptations were recorded for Radio 4. Tom Wilkinson played the lugubrious jazz-buff detective for all of the first three, while Tom Georgeson took over for No 4 (which he could hardly have done on television, having already played a burglar busted by Wilkinson's Resnick in an earlier episode).
"We were trying to find a way to do the programmes on radio in a way that was special to radio," says Harvey. From the novel sequence he chose to adapt No 5, Wasted Years, "partly because it would have been the most difficult anyway to have done on television. It takes place over three different eras in Resnick's life, and radio gives you a tremendous amount of scope to do that." But also, of all the Resnick novels, Wasted Years has the most intrusive jazz soundtrack, "which is much easier to weld in and out of the narrative on radio, to some degree because it's much cheaper to get permission to use music on radio."
To the Manor Born has a head start over other sitcoms awaiting customisation, since Peter Spence actually wrote it for radio before Penelope Keith asked if she could offer it to television. The new radio series is a rare hybrid form of six "classic" (ie second-hand) scripts adapted from the television series bolted on to four original ones commissioned especially for radio. And although the ancestral pile which the widowed Audrey fforbes-Hamilton has been forced to sell gave the television version a distinct pictorial flavour, the show was always more of a comedy of manners than a comedy of manors. In other words, it's a perfect fit for radio. The only question now is whether the dilemma that eventually killed the original show after 21 episodes will recur. "It was very much, `will they, won't they get together?' " Keith recalls, "and I felt we couldn't go on teasing the audience for that much longer."
For the moment, the only shows Radio 2 is reviving seem to be directed at middle-aged audiences of conservative tastes. But we can hazard a prediction based on the station's current policy of hiring once-trendy disc jockeys cast off by Radio 1. Like Steve Wright and Ed Stewart, Father Ted and Men Behaving Badly will not always be at the cutting edge. When the time comes, they can always be put out to grass in the comfortable pastures of 88-90.2 FM, where their currently youthful audience will one day be happy to join them in the sure and certain knowledge that the pictures are, as they always say, better on radio.
The new series of `To the Manor Born' begins 1.30pm today on Radio 2. The new series of `Rumpole for the Defence' begins 8.45pm Friday, also on R2
Jasper Rees reviews the week's TV on page 31