Don't ask me how it happened, but somehow your radio columnist has spent the last few years managing to avoid the Nualas. Oh, sure, I could have spoofed up a definition for a enquiring Martian - "female satirical singing trio" probably. But unlike every other reader of, and writer for, this page, I've never chortled and sung along at a late-night venue, I've never seen them on the telly, I've never even heard them on the radio. As a consequence, I doubt I've ever completed one of the innumerable newspaper articles their comic talents have spawned.

Until now, the damage hadn't told. However, just how deeply uncool this renders me has been driven home mercilessly by BBC Radio 4, which in its wisdom figures the Nualas to be worthy of a summer series, Tuesdays at 6.30 p.m. - repeated, as the girls remind us musically, Wednesdays at half-eleven. The lucky ladies. Radio 4, unlike any station over here, can afford to gamble not only that the Nualas are funny enough for silly season, but that their wit will penetrate minds for whom the euphonious placename "Claremorris" conjures nothing but "somewhere Irish". Described on-air by their fauxDub "manager" Seamus as "Ireland's answer to `who are those Irish girls on the radio?' ", the Nualas carry on the Celtic colonisation of the British public's sense of humour.

Thus their studio audience chuckles at references to a satellite link to Cavan and supergroup John Joe and the Jumpers. And folks who've never heard of Waltons laugh out loud when Nuala signs off: "If you feel like singing, do sing a Nuala song." Well, after my first half-hour with the Nualas, I more or less get the joke. They are, collectively, an excellent stock character for the new Ireland, the fun-loving, semiliberated country girls whose sexual freedom hasn't quite detached them from their mothers' values, nor delivered personal fulfilment. Think Ally McBeal from Tullamore - only funny.

But hilarious? Nah. Their observations are more to provoke a smile than a guffaw. Check out this holiday-romance ditty:

Hey, Manolo, are we an item?/If I go home will you still be writin'?/Do you remember the night, Manolo, when I learned to make paella?/ Do you not understand, my darlin', that that makes you my fella?

See what I mean?

Occasionally they walk a more wicked line, one that satirises "Nuala" while penetrating the mad depths of her anger. Last week's show included one very funny nonmusical metaphor following a young woman, likened to a fresh carton of milk, through her increasingly sour encounters with, first, "a fine cup of tea of a man", then "a dirty old chipped mug of a man". (They're both bastards.)

Please God, Nuala won't end up like poor old Miss Havisham in Great Expectations. Scotsman Ronald Frame's play, Havisham (BBC Radio 3, Sunday) is a sort of prequel to Dickens's novel, focusing on how the malign man-hater in the tattered wedding dress got to be so miserable. The idea is to evoke sympathy for her, so that by the end, when Miss Havisham takes in the young Estella and vows to make her a heartbreaker, we cry "Go get 'em!" - Pip notwithstanding.

It doesn't quite work that way, but as an exercise in literary speculation Frame's drama is a bit of fun. The playwright seems, essentially, to have seen this as a chance to play around with the Victorian novel - complete with the heaving bodices, hints of lesbianism and suggestive riding crops of your typical TV adaptation.

With the obvious theme being the marriagability or otherwise of young Catherine Havisham, Jane Austen is the dominant influence - and Emma the clearest antecedent for the heroine. But there's much more: here a bit of Bronte, there a taste of Middlemarch. You want a (literal) bastard who behaves like a cad? Here you are. A suitor who's not what he seems? No problem. Two learned brothers, one who studies divinity, the other who is up to speed with the latest rational philosophy? Easy.

However, the characters drift in and out with too much ease, and the feisty Miss Havisham is mired in a nasty conspiracy which only she could have failed to perceive at least an hour before the end of the play. What a shame Frame didn't play around a bit more with the plot. Few literary abuses are more annoying than having our credulity mucked with.