"THINGS fall apart, the centre cannot hold," wrote Yeats; and how very wrong he was. At present, the centre is holding so bloody well that it looks as if there won't be anything else left within a few years, not only in politics but in radio.

Talk radio is converging with music radio, radio is converging with television, and the stations are all converging with each other.

At any rate, new "bi-media" departments now reign at the BBC (so the people who make Watchdog and Esther will now also be in charge of all the features at Radio 4 - inspires you with confidence, no?), and TV personalities (Martin Bashir, Peter Snow) abound in the new schedules. Meanwhile Radio 3 seems to be trying to disguise itself as Radio 2 to escape its creditors, and Radio 4's new party-piece is its spot-on imitation of Radio 5. You notice this most with Broadcasting House, Four's new Sunday morning current affairs chat-show - not simply because of the presence of Eddie Mair, a Five Live alumnus, but because it has the free-form, time-filling feel of so much of Radio 5.

The show's most notable innovation has been its glance at the front pages: where other current affairs programme will give you the headlines, Broadcasting House will also give you the plugs for inside features.Since Mair doesn't seem to open the paper to actually read these features, this must be one of the least labour-intensive services offered by any radio programme, as well as one of the least useful.

More interestingly, on Monday, fiction seemed to converge on reality: in On the Whole It's Been Jolly Good, a monologue written by Peter Tinniswood to mark Maurice Denham's 60th year in broadcasting, the actor played Sir Plympton Makepeace, a Tory buffer from the Shires who after 60 years marking time as a backbencher has just lost his seat to one of Blair's babes. Makepeace is a self-indulgent, lazy and not especially intelligent man with few, if any, convictions.

His one contribution to political life was a bill to outlaw traffic on roads frequented by badgers; and he managed to go through the 1980s without registering Margaret Thatcher as anything but "That woman with the loud voice - I think she was the Prime Minister, but to me she looked more like a power-mad swimming baths attendant".

On the other hand, he is kind enough, as long as it doesn't interfere with his pleasures (he is a connoisseur of what he calls "dalliance", and an enthusiastic train-spotter): it is his proud boast that in all his time in Parliament he has done no harm to anybody.

Perhaps it was just Denham's shrewd, energetic performance, but this seemed more concentrated and thoughtful than most of Tinniswood's work - allowing the listener to see the damaging apathy of this sort of genteel reaction, but also to see that there are worse sorts of damage.

It made an intriguing pairing with Collapse of Stout Party, Sir Julian Critchley's daily readings from his autobiography. Not that Sir Julian is as idle and feckless as Sir Plympton; but in Friday's fantasy of how he would have played the last Tory leadership election had he still been in Parliament (hinting support to every candidate, and in return being dined and flattered to the limits of his capacity), there was something of the same modest sensuality, the same humorous scepticism about himself and the business of politics, and the same very reprehensible, but likeable frivolity.