Age can wither them: Will today’s hit plays still be being revived in 50 years' time?

Private Lives and After the Dance both caused a sensation when they appeared in the Thirties and are still being successfully revived. But will today’s hit plays last the course?

Noël Coward and Terence Rattigan were old, half-forgotten names for a new generation of theatre-goers and practitioners, yet recent revivals of their best early work – written when both men were in their late twenties – have been acclaimed as period master works with a biting, contemporary appeal.

Coward's Private Lives (1930), starring Kim Cattrall and Matthew Macfadyen, brushed up as a very modern, high-octane bout of marital bickering among the society hedonists; while Rattigan's After the Dance (1939), starring Benedict Cumberbatch and Nancy Carroll, and still playing at the National Theatre, anatomised a similar social milieu of Bright Young Things as the drink dries up, the money runs out, and the war looms.

The best and brightest of our new young playwrights emerging at the Royal Court hark back, unconsciously no doubt, much more to Coward and Rattigan than to, say, their immediate predecessors Mark (Shopping and Fucking) Ravenhill and Sarah (Blasted) Kane or even, beyond them, to David Hare and John Osborne. The question is: will these new plays be revived in 50 years' time? And if not, does it matter?

One thinks of Polly Stenham, whose That Face (2007) caused a very Noël Coward-type of sensation in its portrait of a dysfunctional family. The quasi-incestuous relationship at its centre was a drink-and-drug-addled retread of the mother-and-son meltdown in Coward's The Vortex (1924), a play whose frankly outrageous dialogue Kenneth Tynan once described as not so much stilted as high-heeled.

That Face didn't become a commercial smash when it transferred to the West End, as The Vortex, Coward's first scandalous success, certainly did. But times have changed, and Stenham, who followed up last year with a terrific second play, Tusk Tusk, about three middle-class children abandoned to their own devices by an unreliable mother, could certainly become a "name" dramatist when she gets out in the world a bit more.

The point is she can write, and she can also write good roles, which is always one guarantee of longevity: the Lilian Braithwaite maternal role in The Vortex is easily matched by the Lindsay Duncan one in That Face. Osborne's Jimmy Porter in Look Back in Anger (1956) remains as essential a hoop to go through for a leading young actor as Hamlet, while David Hare's Plenty (1978), for instance, was reignited 11 years ago by Cate Blanchett as Susan Traherne, the British war-time espionage agent who cannot learn to inhabit the peacetime she helped to secure.

All comedies depend on topical issues and references to succeed with an audience, and maybe a preponderance of these, or at least a preponderance of them unredeemed by metaphorical application, will sink a play's chances of survival. I was struck by this objection being raised by the critic Gilbert Adair against Timberlake Wertenbaker's Three Birds Alighting on a Field (1992). I thought the play was a witty and highly prescient analysis of the art world and allied markets, with a fantastic performance at its centre by Harriet Walter. Only a revival will settle the issue.

The latest Royal Court play to draw breathless critical superlatives, as well as comparisons with Christopher Hampton and Polly Stenham, is Anya Reiss's Spur of the Moment, a precocious take on yet another dysfunctional middle-class family but one virtually throbbing with the authentic pain of youthful observation and sexual anxiety, with an undertow of very bad behaviour. Reiss, incredibly, has just taken her A-levels and wrote the play when she was 17.

But is the play big enough to come back and bite us in 20 years' time? Most new theatre plays have bitty, television-style dialogue, very short scenes, only limited acting and design opportunities. In ensemble companies like Shared Experience and Out of Joint, this is the misguided, democratic point. And theatre plays anyway, despite the still hectic activity, have been outflanked, some critics say, by the newer rash of "immersive," site-specific and audience-baiting performances.

Prominent among these have been Kursk (2009), in which the audience promenaded inside the realistically designed belly of the doomed Russian submarine, or Punchdrunk's recent ENO collaboration on an operatic version of The Duchess of Malfi in which you made your way to an East End of London warehouse and were offered, albeit coercively, the choice of what to do, where to go and what to try and listen to. Punchdrunk's equally "immersive" Masque of the Red Death (2007) was an "event" all right (though rubbish as dramaturgy and piss-poor Poe) and unlikely to be seen again in five years', let alone 20 years', time.

The cry goes up, of course, that this is the point. Theatre is of the moment, by its very nature ephemeral, footprints in the snow, as Richard Eyre once said. But the audiences at Rattigan's After the Dance have been exhaling purrs of positive pleasure at sitting in front of a beautifully crafted piece of theatre machinery that speaks across the ages about joy, love and despair, drink and money, and, above all, what to do with your life. The moment a party scene suddenly flashes up like a mirage is one of the greatest coups I've ever seen inside or outside "immersive" theatre.

We have the most vibrant theatre culture in the world because of our commitment to new work. Look at France: it's pitiful. Germany now does mostly new British plays, if they do new plays at all. David Hare said that the only non-contemporary play he ever felt like directing was King Lear (he made a hash of it, as it happens) but it's people like him, and the Royal Court directors from George Devine and William Gaskill right through to Max Stafford-Clark, Stephen Daldry, and now Dominic Cooke, who keep this flame burning. And the fire still flickers on the fringe.

Because our best actors and directors work with contemporary writers, they return to older masters with renewed relish. Just look at the current West End revivals of Arthur Miller's All My Sons, Neil Simon's The Prisoner of Second Avenue and now, this week, the Willy Russell plays, Shirley Valentine and Educating Rita, at the Trafalgar Studios. These are all plays of between 30 and 50 years vintage, and they are all pulsatingly alive.

This is not achieved by embalming them in a "revivals" museum on Shaftesbury Avenue, as once used to be the case with old plays. Zoë Wanamaker and David Suchet come to Arthur Miller from an embedded, highly trained response to great drama at the RSC, as well as from the hurly-burly of contemporary television. Leading playwright Terry Johnson, directing Neil Simon, has cauterised the mawkishness and sentimentality of Simon in performances by American stars Jeff Goldblum and Mercedes Ruehl that are tart, savage and physically and technically remarkable.

And even since its premiere three months ago at the little Menier Chocolate Factory in Southwark, Educating Rita (1980) has been rethought to such an extent that you almost start to believe that Rita was wrong to embark on the Open University course in the first place; education has drained the life and spontaneity out of her, even though she now has multiple life choices.

Which only goes to show: the best way of treating old plays is as if they were new ones. New plays will come round again in the whirligig of time if they only have sufficient breathing space for re-interpretation, and allow the actor room for the sort of manoeuvre he or she will always find in the richest and most ambitiously daring of new writing for the stage.