I present a weekly arts review programme for Radio 4 and have spent quite a bit of time trying to make the case for criticism in a world of hype. So you might just be able to guess what I feel about the decision to cut The Review Show to one episode a month and shift it to BBC4. If this is an icy wind in the zeitgeist – as some suggested – then it's one that's blowing straight down my neck. And yes, I did get a little Matthew Arnold on reading the news – hearing in my head the "melancholy, long withdrawing roar" of a tide going out. Not religious faith – as it was for Arnold in "Dover Beach" – but the idea that the arts, and more specifically arguing about them, are indispensable to any vigorous culture.

That probably sounds a bit over-dramatic. We're not looking at a civilizational catastrophe here, after all. Just an adjustment in the BBC schedules. But I thought about Arnold because this particular decision seemed to me not so much symptomatic of the BBC's attitudes to the arts but a more historic alteration in the arts' centrality to the culture generally. There are proximate reasons you might advance for the fact that the BBC feels able to marginalise the only general arts discussion programme on television. The growth of blogging and Twitter would be one of them. (Everyone's always been a critic but now everyone who wants to can be a published critic as well, to a degree.) But I think you'd also need to take into account a longer-term tectonic shift.

One simple truth is that the arts used to be a route to the summit at the BBC in a way that they almost certainly aren't just at the moment. Bright, ambitious graduates generally know how to climb in this organisation and there was a time when one path to the top ran through the corporation's arts departments. It wasn't always that way. Light entertainment had its heyday, and serious current affairs too. But for quite a long period in the late Eighties it was arts. That was where the live current ran, through strands like Alan Yentob's Arena and, later, Michael Jackson's creation The Late Show. Neither of them got vast audiences but they felt absolutely central to what the BBC did, and proved a ladder upwards for a number of senior executives.

It's tempting to assume that the influence was a reward for creativity. But The Late Show was able to be as creative as it was because it had the kind of slot, budget and intellectual protection that only existing power can confer. Eventually, fashion shifts though. In the case of television arts, I think we're probably looking at a long slow fade from a Leavisite high-water mark in the Fifties to our current confusion about what counts as serious culture at all. So ITV finally lets the flame flicker out on The South Bank Show and Channel 4 relegates its arts coverage to those backwaters of the schedule where they will do the least damage to its viewing figures. And the ambitious young graduate probably now has his or her eye trained on a job in BBC Science.

The thing about tides, of course, is that they never go out forever, something Arnold's glum narrator seems to forget. If the water's that far down the shingle, perhaps it's about to turn? And I wonder whether that might be the case here. The next Director-General, Tony Hall, did not come up via the arts at the BBC, rising through news and current affairs during his time there. But he's spent a lot of time in the arts since and might not be averse to the idea that they should be at the heart of the BBC's identity. If he chooses to plug the power back in we could all be pleasantly surprised.

Roy was more than just Pop

The revelation of the Roy Lichtenstein show is what an interesting Op artist he was. It isn't a movement that often gets mentioned in connection with him but, as a catalogue essay for the Tate show points out, that's a slightly odd omission. Because it's difficult to look at some of his works and not get a sense that he'd been looking a lot at Op. It's particularly true of his black-and-white canvases, which seem to offer a hybrid of representation and Op-Art dazzle. One of my favourite images in the show is Ball of Twine, in which the object is reduced to a set of overlapping Bridget Riley stripes on a shimmer of Ben Day dots. P(ure) Op.

A chorus of approval for Marber

There's a nice study in stagey self-reference available to London audiences at the moment, with A Chorus Line revived at The Palladium and Patrick Marber's refitted Trelawny of the Wells playing at the Donmar. Here's the paradox though: A Chorus Line is, famously, a sourly disenchanted look in the theatrical mirror – unblinkingly depicting the cruelty of show business. Trelawny of the Wells, by contrast, is positively misty-eyed about the stage. So which turns out to leave you with a greater sense of theatrical self-love? Not Trelawny, which has been skillfully injected with a rueful sense of melancholy by Patrick Marber, but A Chorus Line, presented – a bit like Lenin's corpse – as a perfectly embalmed relic of something too precious to be tinkered with.