It's strangely involving to watch actors struggle heroically in a ludicrous play. When absolutely everything goes wrong on stage, as when everything goes right, we're treated to drama that is urgent, spontaneous, unmistakably alive.

Yet whoever heard of a play in which both extremes of theatergoing pleasure occupy the same stage at the same time? That's what happens at Michael Frayn's "Noises Off."… All three acts of this play recycle the same theatrical catastrophe: We watch a half-dozen has-been and never-were British actors, at different stops on a provincial tour, as they perform the first act of a puerile, door-slamming sex farce titled "Nothing On." With a plot involving wayward plates of sardines, misplaced clothing and an Arab sheik, "Nothing On" is the silliest and most ineptly acted play one could ever hope to encounter. But out of its lunacies, Mr. Frayn has constructed the larger prank of "Noises Off"—which is as cleverly conceived and adroitly performed a farce as Broadway has seen in an age….

It happens that Act I of "Noises Off" is the frantic final run-through of "Nothing On," on the eve of its premiere in the backwater of Weston-Super-Mare. As the run-through is mostly devoted to setting-up what follows, it's also the only sporadically mirthless stretch of Mr. Frayn's play: We're asked to study every ridiculous line and awful performance in "Nothing On" to appreciate the varied replays yet to come. Still, the lags are justified by the payoff: Having painstakingly built his house of cards in Act I, the author brings it crashing down with exponentially accelerating hilarity in Acts II and III.

Indeed, Act II of "Noises Off" … is one of the most sustained slapstick ballets I've ever seen. "Nothing On" is now a month into its tour, and we discover that its actors are carrying out a real-life sex farce that crudely parallels the fictional one they're appearing in. Mr. Frayn lets us see both farces at once, through the device of showing us a chaotic Wednesday matinee of "Nothing On" from the reverse angle of backstage. Everytime an actor playing an illicit lover in "Nothing On" exits through a slamming door, he lands smack in the middle of the illicit love triangles that are destroying the company in private.

Besides being an ingeniously synchronized piece of writing and performing—with daredevil pratfalls and overlapping lines that interlock in midair—Act II of "Noises Off" is also a forceful argument for farce's value as human comedy. Perhaps nothing could top it, and Act III doesn't always succeed….

[But "Noises Off" is a] joyous and loving reminder that the theater really does go on even when the show falls apart….