David Benedict was charmed by the return of 'Black Comedy' and 'The Real Inspector Hound' in a West End double-bill after a 30-year absence
LAUGHTER, as its practitioners will tell you, is a very serious business, yet few theatre commentators take it very seriously. Comedy wins audiences, tragedy wins prizes and admissions that you prefer, say, Much Ado About Nothing to Hamlet should be done in private between consenting adults.

If you herded up the critical fraternity (I use the word advisedly) and asked them to name the truly great plays of the Sixties, the main names in the ring from the heavyweights would undoubtedly be Harold Pinter for The Caretaker and The Homecoming, Edward Bond for Saved and The Pope's Wedding and Samuel Beckett for Happy Days and Play. None of which is noted for reducing audiences to hysterics.

The sustained West End success of contemporary stand-ups such as Eddie Izzard and Jack Dee has led to a preposterous amount of hype surrounding comedy, the first of many art forms to be tiresomely described as "the new rock'n'roll". Anyone would think that no one had ever laughed in a theatre before.

Actually, British theatrical comedy was in very good hands, thanks to the one-off, iconoclastic genius of Joe Orton (notably Loot, Entertaining Mr Sloane and What the Butler Saw). Alan Bennett put down his marker with his hit play Forty Years On, an accomplished satire of the century's life and literature performed by a minor public school. But the two playwrights who left audiences crying with laughter were Peter Shaffer and Tom Stoppard.

Shaffer, a former music critic, had made his mark in 1958 with Five Finger Exercise, a Freudian melodrama in which repressed homosexuality is seen as emanating from what would now be described as "a dysfunctional family unit". His twinned The Private Ear and The Public Eye proved less successful, but he bounced back with another study in male rivalry with John Dexter's famous production of The Royal Hunt of the Sun at Chichester.

It was there, a year later in 1965, that the audiences saw one of the more eye-widening double-bills in theatre history. The first part of the evening consisted of Maggie Smith in Strindberg's Miss Julie. In the second, she came on wearing nothing but a pyjama top as Clea, the spurned mistress, at one of many comic climaxes in Dexter's sensationally cast production of Shaffer's superbly structured, hysterically funny farce Black Comedy.

Meanwhile, Stoppard sprang fully formed from absolutely nowhere on to the Edinburgh Festival Fringe a year later with his celebrated Hamlet re-think Rosencrantz and Guildenstern Are Dead. Hey presto, a star was born. Well, that's what they'd have you believe. Three years earlier, as a 26-year-old reporter on the Western Daily Press, Stoppard had written a play, Enter a Free Man, which found its way on to television in November. With almost Stoppardian irony, his efforts went almost entirely disregarded as it was screened within days of Kennedy's assassination.

By the time the first draft of Rosencrantz and Guildenstern made a splash on the fringe, he had written more TV shorts, radio plays and published a novel. Nonetheless, the National Theatre's 1967 production of the completed Rosencrantz and Guildenstern catapulted him into the stratosphere and one year later, when producer Michael Codron was looking for the second part of a double-bill to pair up with the lightweight (and largely forgotten) comedy The Audition, he turned to Stoppard.

These days, double-bills have all but died out. It is regarded as too much like hard work for audiences to suspend disbelief all over again with an entirely new play after the interval, which puts an additional onus on this new pairing. Yet, the combination of two such highly theatrical pieces is nothing short of inspired. Looking at it, you wonder why no one has thought of it before.

Despite the fact that Black Comedy was little more than a staggeringly good comic idea and a handful of scenes when it went into its original rehearsals, the final result is extraordinarily effective. Shaffer hit upon the notion after a visit to the Peking Opera where he saw a battle scene set in darkness played in full light.

Shaffer's farce opens in complete darkness while struggling sculptor Brindsley and his daffy debutante girlfriend are putting the finishing touches to Brindsley's flat, which he has illicitly redecorated with priceless fixtures and furnishings "borrowed" from his upstairs neighbour, the camp antique dealer Harold Gorringe who a) knows nothing about it, and b) is conveniently away. The reason for all this subterfuge is that Brindsley needs to impress a wealthy collector. And then the fuses blow. The stage is flooded with light but the characters stagger about as if in complete darkness. Shaffer turns the comic screw with masterly precision as Harold and a succession of guests show up who all want the lights back on, to the mounting desperation of Brindsley et al.

It's just as hard to describe exactly why Stoppard's comedy The Real Inspector Hound is quite so funny. Two gloriously pompous and pretentious theatre critics, Birdboot and Moon, are pontificating on stage about a country house murder mystery they (and we) are about to see. Everything looks set for a splendidly spirited pastiche of Agatha Christie complete with an escaped madman and char lady, Mrs Drudge, who has a nice line in expository telephone conversations along the lines of "Hello, the drawing room of Lady Muldoon's country residence one morning in early Spring?"

The play's original director Robert Chetwyn strongly believes that the play is by no means simply comic. Chetwyn started the proceedings with the critics at the back of the set but at the point at which they enter the action the set moved them to the front. He said: "It was as if the earth shifted beneath your feet. By the end you didn't think you'd only seen a farce. Something very interesting and peculiar was going on underneath."

The other link between the two is their use of stereotypes. Black Comedy includes collisions between an elderly spinster, a blonde sex-bomb and a predatory Northern queen (and that's just for starters). The Real Inspector Hound features dim policemen, "young gels" and a wheelchair-bound, crippled half-brother.

Yet, however helpless the hysteria they induce, they remain types. It took Joe Orton or, more recently, Terry Johnson in Hysteria and Dead Funny to write this level of humour without resorting to stereotype.

To Saturday, at Richmond Theatre, Richmond, Surrey, (0181-940 0088). From 16 April, at Comedy Theatre, London WC2 (0171-369 1731).