Life upon the wicked stage, wrote Oscar Hammerstein, ain't nothin' like a girl supposes. I'll say. Seventy years on, as if to underline the futility of theatrical aspirations, there now seems to be a distinct actuarial disadvantage. A couple of years back, it was Jonathan Larson dying on the eve of his triumph with Rent. Last month, the author of James Baldwin: A Soul on Fire could have woken up and read a rave review in the Times of his first major New York production. Unfortunately, he didn't wake up at all: he had fallen into a coma and died later that day. Howard Simon was thirty-seven, more or less the same age as Larson.

When the fates play a trick most contemporary dramatists would recoil from using, it's tempting to ponder what they mean by it. In 1980, when Gower Champion, with the impeccable timing that characterized his best work, expired a few hours before the curtain rose on the premiere of 42nd Street, it was an apt if freakish finale to a splendid career. In the New York theater these days, the final curtain is as likely to fall during previews—as if to say abandon hope all ye who enter here. In the case of Larson, we were supposed to have been robbed—of another dozen great shows that this promising young man would have written. I didn't think so: Rent was like Meredith Willson's Music Man—one of those shows that feels like the only show the guy has in him and that he, in turn, has poured everything into. He may go on, as Willson did, to write other works on other subjects, but never with the same commitment and identification.

Simon, though, is a different case. On the evidence of his play (produced by the New Federal Theater at Abrons Art Center), he would have enjoyed a dogged career of respectable productions that never quite ignite into hits. James Baldwin: A Soul on Fire pushes all the right buttons, sometimes crassly so. The play is set in 1963, as Baldwin and his fellow activists Lena Horne, Lorraine Hansberry, and Harry Belafonte are preparing to meet with Robert F. Kennedy. Baldwin is all of a tizzy, for RFK is, as he says, “so manly.” But matters are complicated by an ill-advised bit of rough trade from the night before who's kidnapped the author's latest manuscript and is demanding a big payoff. This is a typical Equity-scale production in our turn-of-the-century theater: two actors, one of whom plays Baldwin while the other mops up everyone else—from Lena Horne to Huey Newton, not to mention a one-man chorus cum deus ex machina called Ethereal. I suppose Simon, like all other budding playwrights, knew enough not to write a play requiring six actors, but, as so often nowadays, the character of Ethereal and the requirement of Forrest McClendon to play Everyone But Baldwin seem like devices—they don't arise organically from the material.

Simon has the benefit of a winsome central performance by the Baldwin-like Charles Reese, which helps mitigate the often suffocating, manipulative tone of Chuck Patterson's production. This Baldwin sings and coerces the audience into clapping along until we are one united, life-affirming congregation. To be honest, I was probably the only one who needed to be coerced. But then I resent clapping along at Riverdance. It seems even more inappropriate at a play—unless it has a very specific function, as in Peter Pan, where our applause is needed—“Do you believe in fairies, boys and girls?”—in order to restore Tinkerbell to life. I think it safe to say that, if you don't believe in fairies, you're unlikely to be at a play about James Baldwin. But, even so, in most dramas the happy-clappy routine has a faintly fascistic whiff about it—you have to be very strong-willed indeed to sit on your hands—and it's used as an unearned shortcut—a way of announcing the character's virtue rather than persuading you of it. In a similar vein, a film image of the real Baldwin is projected on to the stage. And even the title, James Baldwin: A Soul on Fire, sounds more like a book than an evening of drama.

These are not the faults of the late Mr. Simon so much as the theatrical culture in which he hoped to make his name. Indeed, the New York theater would not see any of the above as faults at all. It may well be the case, as we're often told, that systemic racism and homophobia are so deeply ingrained in America that we need to have plays on the same handful of subjects for the next millennium or three. But if I were to offer any advice to the students at NYU's graduate writing program, where Mr. Simon learned his craft from the likes of Tony Kushner, it would be this: write what you don't know. This is, apart from anything else, a commercial judgment—the black and gay markets are pretty crowded these days—but it offers artistic benefits, too. One reason for the death of the American straight play must surely be because so many are as parochial and self-absorbed as the conversation at the adjoining table in a downtown restaurant.

Consider, by way of contrast, Michael Frayn's Copenhagen (at the Royale). Like Simon and that 1963 meeting with Robert Kennedy, Frayn has been struck by a small historical incident: in 1941, when most of Europe was under German rule, Werner Heisenberg, the head of the Reich's nuclear program, paid a short visit to occupied Copenhagen to look up his old mentor, Niels Bohr. That one verifiable fact is really all Frayn has to go on. No one knows what transpired during that trip, but, for a good playwright, that's all the more fun. Frayn likes to make connections: in this instance, Heisenberg was already at work on a German atomic bomb; Bohr would soon be whisked out of the Reich and on to the U.S., where he worked on the Manhattan Project. So the question is: what would two Nobel-winning scientists with a shared interest in nuclear fission find to talk about in 1941? Heisenberg could have obtained some essential information from Bohr. Did he ask? Did Bohr, a Danish Jew (half-Jew, actually, though the Reich did not disdain fractions), find a way to avoid telling him? Or was Heisenberg only willing to go so far to help Hitler to victory? Did he go out of his way not to ask what he needed to know? Did he perhaps urge Bohr to warn the Allies that the Germans were also on the case? Was he seeking his teacher's blessing for the apocalyptic work on which he was engaged? Or was he only there, as Bohr's wife Margrethe sneers, to show off?

What we have here then is a work of speculation, in which the goodguy/badguy roles don't come preassigned and on which the end of the war may hang, and thereby the postwar world in which we live. As Frayn acknowledges, he's not the first to seek parallels between Heisenberg's work and his life. David Cassidy did so in his biography Uncertainty. (I assume this is not the same David Cassidy who was once a teen heartthrob with the Partridge Family, and whose solo hit “How Can I Be Sure?,” seems with hindsight to be in a Heisenbergian vein.) It's an interesting idea for a play … On second thought, scrub that last sentence: Among his other achievements here, Frayn, a playful linguist, demonstrates how worthless the word “interesting” is as an adjective. So let's look at it this way: when critics bemoan the decaying of Broadway into Disneyfied mega-spectacles, they usually miss the point. At the heart of most satisfying theater is something big. That doesn't mean you need Miss Saigon's helicopter to express it. But even a small three-handed bare-set play ought to have something big at its core.

Here, Frayn, hitherto a funnyman best known for the farce Noises Off, is venturing into Tom Stoppard territory—exploring little corners of history's vast sweeping canvas. Like Stoppard with Arcadia and Hapgood, he's been accused with this play of being too cool and cerebral, but, if the alternative is feeling good about clapping along with James Baldwin, Fraynian cool offers a greater likelihood that there might be an outbreak of … drama. And so it proves. Copenhagen is on Broadway, but his set is as sparse as Howard Simon's—just three chairs in a kind of lecture-hall limbo, round which the protagonists prowl as they explore Frayn's various versions of historical truth. His conclusion is an extrapolation of Heisenberg's famous Uncertainty Principle about the movement of electrons into a general theory on the “uncertainty at the heart of things.” The straightforward geographic title of Copenhagen gives us a clue to what drew Frayn to the story: the scientific world's Uncertainty Principle man comes to Denmark, home of the man who symbolizes drama's Uncertainty Principle: Hamlet. Frayn has combined these twin strands into a great rumination on the certainties of science, and the uncertainties of the human motivations that drive it.

I first saw Copenhagen in London on the National Theatre's smallest stage—the Cottesloe, where Michael Blakemore's production pulled off a wonderful dual effect, conveying both a very immediate intimacy and the sense of huge forces pressing in from the world outside. You expect some of that to be lost in Blakemore's restaging for a Broadway house, but what's more surprising is how much is retained. Much of that is due to three terrific performances—Michael Cumpsty as the torn Heisenberg, Philip Bosco and Blair Brown as the affable Mr. and Mrs. Bohr. They manage to convey both the immense ordinariness of lowly figures caught up in a great war and the extraordinary genius on which the outcome of that war may depend. As in Stoppard's Arcadia, Frayn's Copenhagen uses scientific principles to illuminate emotional truths—and, aside from physics, history, and philosophy, the play is suffused in primal human feelings: Bohr has lost two children and hopes in Heisenberg for a surrogate son. There is, in theory, no reason why an Englishman of Frayn's background should be any more interested in a Dane and a German getting together in 1941 than a New York playwright would be. Are the defining events of the modern world of no interest to American dramatists?