Snowbell I think I know what you mean by "middlebrow" in relation to theatre. I too live out in the sticks, and a lot of the productions on offer are very unchallenging, to say the least.
The gulf in quality between (say) the Lyric Theatre in Hammersmith and the kind of plays they put on in Reading or High Wycombe is unbelievable. Is it because the typical audiences are very different outside the big cities, I wonder ? Too many "detective thriller" plays and unfunny farces. These are just plays that don't even try to aim high, perhaps we can call them "lowbrow". (But again, why should those genres be unchallenging ? There are great thrillers and farces in books, films etc.)

I suspect that plays you describe as "middlebrow" are those plays which purport to aim a little higher, and tell us something about real life, but do no such thing. There are no surprises, no interesting takes on the world, no sense of challenge, edginess or anarchy. Two plays I remember from long ago that suffered from this were Burn This and Frankie And Johnny in the Claire De Lune, quite the most excruciatingly boring thing I have ever been to see. (Although Dancing At Lughnasa comes close. And I absolutely detest the clever-clever showoffishness of Pinter's plays, but at least you can see he's doing something interesting.)

Anyway I'm off to see John Mortimer's show in Islington this weekend, so I can't wait.

Oh relief! I think you've understood what I was on about Griff. You are really good at explaining things in a sentence that I have to take seventeen paragraphs over and still have people misunderstanding.

I suspect that plays you describe as "middlebrow" are those plays which purport to aim a little higher

I think I don't object to anything trying to do something. I don't even honest attempt that don't work or even fail. What I really don't like are smug things that purport to be "better" in some way than the rest, where the audience can go on about their edifying experience, but actually there was nothing there at all except the odd symbol of profundity. I suppose I find those kind of things lazy, smug and dishonest and I don't like the way people feel superior for watching them rather than - as you say - a great detective piece or comedy, which they might look down their noses at.

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I don't object to an honest attempt that doesn't work or even fails.

Sorry my posts are REALLY deteriorating.

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Sorry that wasn't supposed to be patronising to everyone else. But I realised after my great rant that everyone being into books would probably mean they didn't have a clue what I was on about and it might have been a bit of a personal rant...