NO SOONER had I dismissed, in last week's column, the prospects for a jazz/blues station to thrive on one of the new Dublin commercial "niche" licences than my colleague Jackie Bourke - my much-needed arbiter of all things cool post-1981 - told me to check out Jazz FM.

A great argument for spinning dials rather than pressing pre-set buttons, Jazz FM is an unlicensed station (a "pirate" to you landlubbers) nestled snugly between RTE Radio 1 and 2FM. It plays, according to the sultry voice that follows the signature tune, "the best underground sounds, 24-seven". Once I figured it out, I decided "24-seven" was dead cool.

In the week I've listened (a lot) I've heard very little straight jazz, apart from nice, lightweight stuff on Monday morning; but I've heard soul, reggae, funk and some hiphop that's seriously "raw" - i.e. don't look in The Irish Times for quotes from the lyrics. In fact, apart from Sunday morning when Elvis, Johnny Cash and Nancy (yes, Nancy) Sinatra turned up, the main qualification for being played on Jazz FM seems to be ample skin pigmentation.

And what a welcome corrective. Leaving aside John Kelly, even the supposedly tasteful and knowledgeable presenters on RTE Radio 1, notably Carrie Crowley and John Creedon, play a selection of CD-fodder from a shockingly high proportion of paleface performers. Years after the demise of RTE's "no jazz" policy, you're more likely, I think, to hear Benny Goodman than Duke Ellington - and when Carrie Crowley promises a piece of "urban jazzy folk", it turns out to be Donovan.

It's wonderful the stuff that comes in the post when you're a highly influential radio critic. So I'd imagine anyway, because even the likes of me occasionally gets something vaguely interesting; indulge me while I tell you about it.

Last week's largely uninspiring JNLR/MRBI figures for radio listening provoked, as usual, a small flurry of boring press releases. However, the occasion also gave Today FM an excuse to send out, to me and no doubt many others, a "Mop Top" - one of those stuffed socks with a face drawn on the front and the "scalp" liberally planted with seeds (just add water, repeatedly).

I think it's supposed to be some metaphor for the station's development, but I can't help thinking that listening to Today FM is about as exciting as watching grass grow. (I am, of course, nurturing it lovingly - no grass yet.)

Then came the anonymous letter in an RTE envelope. Typed on a computer entirely in roaring CAPITAL LETTERS, it eschews salutations and gets straight to the point: "Before you do down Marian Finucane completely, bear the following (sic) in mind;" then it proceeds with three numbered points, two of which have nothing to do with Blessed Marian. The one that does refer to Finucane chastises me for citing, in an analysis article in last Wednesday's Irish Times, the very high 1998 ratings for Liveline, Marian's last spin in that afternoon slot. Anonymous correctly points out that the programme was 75 minutes long for most of that year, so its cumulative audience would be higher than when it's lasted just an hour. "Its (sic) clear you are lining up to compare her 99 figures."

That's a clarity about my intentions that I envy. Moreover, it's really clear that the Anonymous Letters Department is out of touch with RTE's PR Department, which boasted about the highest-ever Liveline ratings near the top of last week's press release. Point Two is a washout, but Anonymous Point Three has a bit of bite: "We know you hate 5-7 Live, but despite your two year campaign for Dunphy, it is still higher than The Last Word despite your spin from the Today marketeers - at least have the good grace to say it."

That's a case of mistaken identity in spades. I hope Anonymous isn't (aren't?) in journalism, because in fact I didn't quote any spin from Today FM or anyone else last week; quotes from that station's spokesman, plus others from RTE's Helen Shaw, were in a separate news report. I actually poured cold water on most of Today FM's ratings hype (like I'm doing with the Mop Top), though not specifically about The Last Word, which is undoubtedly an oasis of success. As for Five Seven Live, I've probably praised Myles Dungan more wholeheartedly than any other radio presenter and written mostly approvingly of the programme's lively style.

At any rate, it's not my job to report on every ratings battle. Next week, I might even write about radio programmes.