Scene 1: Daytime interior; room in Watergate Hotel - posh but disorderly. Open candy boxes are distributed at strategic locations.

STOPPARD is speaking on the telephone, which sits atop a chest of drawers, his lanky, dark-haired form reflected in a mirror behind the chest.

STOPPARD: (aside to interviewer) "Please excuse me for a moment; my bags have apparently gone on to Los Angeles and I have to track them down. (Into telephone): Yes, Tom Stoppard here. Has a suitcase arrived for me from British Airways?"

TELEPHONE: (inaudible)

STOPPARD: "Okay, thanks . . . Yes, I'm leaving the room an hour from now, I've got to go to the Kennedy Center. Yes . . . Yes, thank you.

(Begins looking around room.) "Where is my . . . Let me think . . . I've just gone with Andre to a shop; he had to pick something up and I said I'd walk with him. Now, did I have my? . . . Oh, God . . . I'm sorry, very sorry, but I'm going to have to waste 10 minutes going back, because I've lost my bag with my passport, my money, my wallet, my credit cards . . .

"Because my suitcase went astray, I went to the barber shop to be shaved. I don't know whether I left it in the barber shop or in the breakfast room . . . I'll call the breakfast room."

STOPPARD: (Dials telephone.) "This is Mr. Stoppard: I had breakfast this morning with Andre Previn and I think I may have left a black leather bag in the corner by the window . . . Yes . . . (long pause) Hello. Did you find it? Okay, I'll try somewhere else. Thanks.

(Dials again.) "Hello, barber shop?This is Mr. Stoppard. You shaved me this morning, or somebody did. Did I leave a black leather bag there? Right opposite where I was sitting . . . Yes? Okay, thank you. (hangs up) I suppose I should call Andre and ask him . . .

(Dials - long pause - dials again.) "Oh, I think I have the wrong number, actually; I'm trying to get Gucci's in Les Champs (his French is exquisitely precise). Thank you. (dials again) I was just in you shop with Andre Previn a few minutes ago. Did I leave my bag there? (long pause; room service enters with coffee.)

STOPPARD: (still on phone to Gucci) "Did I leave a black leather bag there . . . just on the counter where ther shirts are . . . Is this Gucci in Les Champs? This is Tom Stoppard. I'm in the Watergate Hotel. S-T-O-P-P-A-R-D. (hangs up) I'll have to go down and see. (Exit)

STOPPARD: (Enters, stage left, carrying black leather shoulder bag) "It was in the restaurant, exactly where I said it was."

INTERVIEWER: "Mr. Stoppard, do you think that life is a situation comedy?"

STOPPARD: "That's not a real question. Or maybe it's too profound for me at this time of morning. Try to do the right thing for the next five minutes. That's my philosophy of life.

Even when he is not starring in his own private comedy, Tom Stoppard's life has the lack of inherent probability that runs through his drama. (Born in Czechoslovakia in 1937, he was an unlikely prospect to become England's most popular English playwright in this country). But after several years as a journalist (and with time out for one novel) that is what he became.

The road to England led through Singapore, where is family moved shortly before Hitler's invasion of Czechoslovakia. His father died in Singapore during the Japanese occupation, but he escaped with his mother, who later married a British military officer. That is the life that has led to "Rosencrantz and Guildenstern Are Dead," "The Real Inspector Hound," "Jumpers," "Travesties," and "Dirty Linen."

Stoppard's manner, like his dress, is richly casual; light sport jacket with darker trousers, shirt-collar unbuttoned and a necktie around his neck but loosely, not tied. He speaks easily, fluently hitting the precise word the first time with practically no hesitation or backtracking, and the words flow naturally into paragraphs.

He sounds very much like his own dialogue-casual, colloquial, but tightly knit, with the exception that (unlike some of his characters) he is always precisely aware of what he is saying, where the conservation is and where it is heading.

Where it is heading now is to rehearsal for "Every Good Boy Deserves Favor," which opens tonight at the Kennedy Center, and includes a 90-piece symphony orchestra in its cast of characters.

The orchestra was the idea of another adopted Englishman, Andre Previn, who has become England's most popular conductor (or at least in this country), and it took Stoppard several years to get Previn's ideas lined up with his own.

Orginally, he recalls, "Andre asked me whether there was any possibility of doing a play . . . well, not necessarily a play, but something with orchestra - he could write some music and I could write some words."

Stoppard began tinkering with the idea of a millionaire who owns a symphony orchestra, then a millionaire who only thinks he owns a symphony orchestra. At this point, it occurred to him that if the man only thinks he owns an orchestra, he doesn't have to be a millionaire, and so he was working on the story of a madman who thinks he owns an orchestra.

Coincidentally, he became acquainted with Victor Fainberg, a Russian who had protested in Red Square against the Russian invasion of Czechoslovakia 10 years ago.

"Fainberg was put into a psychiatric hospital/prison in Leningrad, and was subjected to all sorts of horrible experiences," Stoppard recalls. "But he's a very tough man; and in the end, he beat the system. He was such trouble that they finally eased him out and got rid of him.

"The story of Fainberg suddenly tied in with my strangulated efforts to write this piece for Andre; it became the story of a sane man locked up with mental patients for his political activities.

"And once it became that kind of a play, everything was fine. Even stuff that I'd written abortively, without knowing what to do with it, began to fit in."

That experience is not unusual for Stoppard. "The stuff I write tends to work itself out in comedy terms most of the time. When I told Andre that this probably wouldn't be a comedy piece, I was quite wrong, I'm afraid."

One wonders, thinking about Stoppard's work, observing him in the embroilments of lost luggage and passport, whether he lives in exactly the same world that most other people inhabit.

As reflected in his plays, it seems recognizable but subtly different - more complicated, a bit confusing (or perhaps simply more aware of the circumambient confusion), but inexporably bound in a logic of its own. Much of what happens in that world happens in imagination or memory (one can't always be sure which), and the focus is a bit unusual. Rosencrantz and Guildenstern - drift to the center of the action without quite knowing how they got there.

He enjoys this out-of-focus perspective when he finds it in others and tells with relish about a conversation in a restaurant with a Washingtonian who did not know who he was. She told him about how "I saw a radio play of Stoppard's called 'Albert's Bridge,' which was put on in a staged version here. I loved it, and ever since this play I've been to every play by Tom Stoppard that I could get to and you know, I never liked him again."

Discussing with Stoppard how a play is made, one can easily get the impression that he is sometimes a bemused bystander watching a process that is not wholly within his control. He usually has several germinal ideas in his mind which, to his surprise, "at a certain point turn out to be parts of the same play."

"I'm not somebody who has a great, wonderful list of ideas for plays that I can turn to - stuff to keep me busy for years ahead," he observes. "I find it very difficult to get ideas for a play at all. I find that most of the trouble for me is inventing a story to contain the ideas that I want to write about.

"In the case of 'Every Good Boy,' the problem was to invent a reason for having an orchestra. It's no good just having six brilliant things to say, with some music. You've got to invent a story which has its own hold on the audience."

Compared to writing a novel (he has published one, "Lord Malquist & Mr. Moon"). Stoppard finds that "Live theatre is a very dangerous, unstable activity."

"The advantage of a novel is that it stays the way you let it, and that's also the disadvantage. In live theatre, you can't really control what happens to your stuff, because it wouldn't be any good if the performers weren't making their own contribution. It balances out.

"But it is alarming. If you have something running for quite a while and you visit it from time to time, you can hit a dud night and get thoroughly depressed at what you've written. Or you can go there terribly worried about how it's holding up and have a terrific night when it works beautifully."

The next Stoppard work is "a play which is going into rehearsal in London next month. It's about British journalists - foreign correspondents - not about Cole Porter."

"Unless I do a rewrite, which I might."

Suddenly, Stoppard's phone rings again. It is the airline.

STOPPARD: "The bag is not in Los Angeles? You don't know where it is? I must have that bag in New York tomorrow. Please have it sent to New York. Oh, dear; I don't know what New York hotel I'll be stopping at . . . (His voice trails off).

INTERVIEWER: (Opening door to leave) "Material for a Stoppard comedy?"

STOPPARD: "Sounds more like Pinter to me."