Thinking in the second-chance saloon

Theatre-goers are familiar enough with the idea of plays within plays, in the sense of a piece of drama in which a play is staged as part of the action: take Hamlet, The Seagull or Noises Off. But what about that other kind of play within the play: a work by a dramatist which has its foundations in a previous work by that same writer?

Two of the biggest recent West End openings - Tom Stoppard's Indian Ink and Simon Gray's Cell Mates - have an unusual factor in common, of which listeners to Stoppard's 1991 radio play In the Native State and Gray's 1994 radio play With a Nod and a Bow will be aware. Neither of the stage plays is merely an adaptation of its sound predecessor, although themes and characters are common to both versions; rather, both stage plays are written from the same material as earlier radio versions. It is a genre which might be called second-chance drama, and Stoppard and Gray are its foremost exponents.

A majority of Stoppard's plays have some kind of alter-evening or doppel- drama in their background. In 1964, for one night only in Berlin, there ran a one-act verse farce called Rosencrantz and Guildenstern Meet King Lear. It was not much liked but Stoppard, a young writer on a German scholarship, had the presence of mind to switch from poetry to prose and rework the same idea into Rosencrantz and Guildenstern Are Dead, which, in 1967, became one of the most successful modern stage plays.

Bankable after that success, Stoppard wrote in the same year a television play called Another Moon Called Earth: a half-hour piece about an absent- minded historian whose glamorous wife takes to her bed with depression after witnessing the first man walking on the moon. The play was not well received. George Melly, then television critic of the Observer, felt it to be "an improbable fable", adding, "the language... had something of the fussy, dated quality of Christopher Fry". Five years passed, during which time man really did walk on the moon, and Stoppard had sufficient faith in material dismissed by television critics to rework its central elements into a stage play, Jumpers, which became a hit.

If Stoppard's subsequent work shows few such direct examples of two coats cut from the same cloth, there are many cases of, say, a jacket and a pair of trousers tailored from the same material. An interest in Eastern European dissidence produced, during 1977, a stage play (Every Good Boy Deserves Favour) and a television play (Professional Foul). An interest in espionage and the spy novels of John Le Carr was the source for The Dog It Was That Died (radio, 1981) and Hapgood (stage, 1988).

And finally, this week, Stoppard's reputation as a writer who will try anything twice is confirmed by the emergence of Indian Ink at the Aldwych from the wireless chrysalis of In the Native State.

Simon Gray, too, has a history of playing with his own plays. Otherwise Engaged, which began a long West End run in 1975, and Dog Days, which had a short run at Watford in 1976, were versions of the same play, the latter being, as it were, an imperfection of the first. Similarly, the list of Gray's previous stage works in his published scripts includes one called Melon and another called The Holy Terror. In fact, these works share the same characters and basic plot, and are both based on Stuart Sutherland's book Breakdown, although the dialogue only rarely matches.

Dissatisfied with Melon during its London run in 1987, Gray began to tinker with it, eventually ending up with a wholly new script called The Holy Terror, performed on BBC radio and then off-Broadway. Finally, research into the springing from jail of the spy George Blake produced an unperformed stage play called Says I, Says He which became the Radio 3 play With a Nod and a Bow and, now, the stage play Cell Mates.

The first explanation for this tendency to write drafts in public is practical. Throughout his career, Stoppard has complained of a shortage of ideas for plays. There is no fat folder of future projects; each curtain- line brings him to a halt. Given that his principal aim is to produce full-length stage plays - of which there have been only nine in a 30-year career, compared to Gray's 16 or Ayckbourn's 40-something - there would be a certain pain in discovering that he had "wasted" a good idea or useful material on radio or television. Pressed once on the connection between Jumpers and the earlier Another Moon Called Earth on TV, Stoppard delivered one of his disarming epigrams: "If an idea's worth having once, it's worth having twice."

There is something of the same creative thrift in Simon Gray - he has expressed an interest in adapting his television film After Pilkington for the stage - but his revisits and revisions seem more often to result from aninsistence that a certain block of work does definitely somewhere contain a successful play; Melon / The Holy Terror is the best example, but The Common Pursuit is another - after failing to reach the West End from Hammersmith in 1982, it made made it six years later, with the same title but a largely different script, after being staged by Gray in Los Angeles, Dallas, New York and Watford in successive rewrites. (Stoppard has expended the same paramedic energy on his least successful major play, Hapgood, which recently turned up substantially rewritten in New York, six years after its West End closure.)

This process raises commercial questions as well as creative ones. In the late 1970s, when a Brian Clark play called Whose Life Is It Anyway? was premiered in the West End, some critics felt that it was unlikely to succeed, and was even a somewhat cheeky project, because it was a version of a recent Clark television play. In fact, this euthanasia drama had a long and lucrative life in London and around the world, and subsequently became a film.

Although producers often remain nervous about admitting a project's generic history - the advertising for Indian Ink doesn't exactly yell its connection with In the Native State - one of the most surprising commercial discoveries of recent years has been that there is little consumer resistance to the reproduction of material in different media. Shadowlands, William Nicholson's West End, Broadway and subsequent movie hit, had been shown at least three times as a television play within recent memory prior to its staging, theoretically knocking out millions of potential customers. In reality, the small-screen version seems to have functioned as an advertising campaign for the eventual theatre version.

It should be made clear that this is not a complaint under the Trade Descriptions Act, or a call for safeguards on generic experiments. My interest in these examples is the light they shed on notions of "originality" and "theatricality". Reading side by side the published Faber & Faber texts of Stoppard's In the Native State and Indian Ink is a fascinating lesson in generic restraints and possibilities.

In the most obvious example, Indian Ink has already received much publicity for featuring Felicity Kendal's first nude scene, but it is, in fact, her second: the first was on Radio 3 in In The Native State. Indeed, Felicity Kendal nude on radio was a very Stoppardian joke, which now becomes a tawdry stage convention. There is also a moment in In the Native State which employs radio drama's favourite trick: the description of fantastical sights - a parade of extraordinary vintage cars - which the listener builds up in their mind's eye. Interestingly, the writer has maintained this scene in the stage script, without real cars, and relying again on the mind's eye. Requiring the audience to use visual imagination in a visual medium transforms a standard radio convention into a risky stage one.

The final line is rarely the last word. There is always a play within a play.