If it's true that hard work never killed anyone, Sir Alan Ayckbourn surely will live forever.

Ambitious and prodigious, with more than 70 plays (and counting) behind him, the 72-year-old Ayckbourn has made his name with a pointedly loquacious style of character-driven theater. He's been rewarded with two Tony Awards (one for lifetime achievement), several Tony nominations, a Laurence Olivier Award, a Critics' Circle Award for Distinguished Service to the Arts, and a knighthood.

This week, Philadelphia's Wilma Theater opens its first Ayckbourn play, My Wonderful Day, a curiosity in the British playwright's oeuvre: Its focus is a black child.

Dialogue-rich but decidedly nonliterary, the vast majority of Ayckbourn's plays satirize the manners and morés of the white middle class, its tedious and often contradictory conventions - marriage, in particular. Like Noel Coward but without the stiff-upper-lip snark, he is a mirthful mocker of those living out the drab suburban dream.

"To direct an Ayckbourn play, you really need someone who is knowledgeable about human foibles," says Richard Hamburger, emeritus artistic director of the Dallas Theater Center, who is directing the Wilma's My Wonderful Day. "A good sense of humor, timing, and a propensity for precision are Ayckbourn necessities as well."

In wall-to-wall-wordy plays from How the Other Half Loves (1969) to The Norman Conquests (1973) to Time of My Life (1992), Ayckbourn has let his audiences eavesdrop on the mundane parlor conversations and neurotic bedroom natterings of Britain's burgherdom, to wildly comic effect. As critic Harold Clurman once wrote, he is "a master hand at turning the bitter apathy, the stale absurdity which most English playwrights now find characteristic of Britain's lower-middle-class existence into hilarious comedy."

And then there is My Wonderful Day.

The 2009 play, which premiered at the Stephen Joseph Theatre in Scarborough, Ayckbourn's home stage, then skipped London and went straight to Broadway, is his first written specifically for a black character - 9-year-old Winnie, daughter of Laverne, an Afro-Caribbean housekeeper. More significant, it is the first time a child has had a lead role in an Ayckbourn play for adults. This isn't one of his occasional forays into children's theater - it's a catty, class-centric grown-up play with a witty child at its center.

"Ayckbourn's principle preoccupation here," says Hamburger, "is with the way we take each other for granted and how children see and hear everything we do."

In My Wonderful Day, Winnie accompanies her heavily pregnant mother to the London home of Laverne's wealthy employers, who don't seem keen on children. "Adults often talk down to kids, and, because children are often powerless to overtly speak up, adults will frequently delude themselves into believing they're not being observed," says Hamburger, who adds that being a parent has been integral to his work on My Wonderful Day. "Ayckbourn very skillfully and with lots of humor extends this habit of denial to how we treat people of the opposite sex, employees, and those of a different class."

While laboring over a homework assignment to chronicle a "wonderful day," Winnie stumbles on more than a few of the house's secrets, including a particularly nasty and tangled love affair. Laughs ensue, truly wicked ones that poke fun at the tired British class system. Hamburger says that Ayckbourn, as he ages, seems to want to enlarge his field of vision, taking "a more expansive perspective of upper-middle-class life by observing it through the eyes of an Afro-Caribbean kid and housekeeper's daughter."

Hamburger says My Wonderful Day is not "talking head" theater but rather an odd assortment of characters from different social layers of London observed through the relatively unconditioned eyes of Winnie as they embroil themselves in all manner of pickles.

Though Henry James' What Maisie Knew may have inspired Ayckbourn's tale, surely Frances Hodgson Burnett's The Secret Garden played a part. Hamburger notes that Winnie is reading The Secret Garden, which features a world "teeming with life beneath what can appear to be dull, barren - where children can be trusted to follow their impulses and learn from each other." In the book, children left to their own devices develop deep and harmonious inner lives. "There are parallels there with Winnie's experience of her wonderful day."

Beyond his firsts with Afro-Caribbean characters and children speaking wisely in adult situations is Ayckbourn's uncharacteristic spareness and concision in this play. There are great rests in its musicality, scores of silences and deep pauses that can convey as much as his usual densely packed chatter, a new sense of rest and space that began, albeit cautiously, with Ayckbourn's 2004 Private Fears in Public Places. Like the most perfect short story - Hemingway's "Hills Like White Elephants," Burroughs' "Roosevelt After Inauguration," Cheever's "The Country Husband" - Ayckbourn has found a new, uncluttered way to accurately describe his people, places, and their farcical circumstances.

"We've attempted to make the silences and spaces as potent and active as the spoken sections," says Hamburger. "When we aren't talking, we still want things, we are frightened, the emotional temperature can be hot. In other words, life goes on. Yet frequently in theater little attention is paid to these caesuras in speech.

"Deadening out when someone isn't talking is an unfortunate convention of a deadly kind of theater, so I see it as a maturing in Ayckbourn's development that he has written them in, and we trust that that they will hold the attention of the audience."

Or, as Ayckbourn says in his notes to My Wonderful Day, "I'm 73 [plays] on, but I still want to try and push myself into new areas. What you learn is that you've been overwriting for most of your life."