Murphy Guyer is a playwright and an actor. He was not, at least until six months ago, when he started playing Capt. George Brackett in South Pacific, much of a musical-theater guy. "I had been in a couple of Brecht plays years ago where I had to sing," he says. "But that was less about singing than about conveying a message." Asked about the possibility of assuming another role in SP, one that might require a trill or two, he responds, "I'm not a trained singer, so that would be terrifying, not just for me but for the audience."

What he does do in SP, and do with persuasive authority, is play a character who is itching to get into "the shooting war," but who is stuck on an island. "I don't just think of myself as playing Brackett," Guyer says, "I think of myself as half of a team: Brackett and Harbison." Harbison is Cmdr. William Harbison, portrayed by Sean Cullen.

"Two-man acts were popular in the 1940s," Guyer says. "And the two partners were usually opposites, as we see in South Pacific. Harbison is college-educated. He operates by the military code. Brackett is more of a seat-of-the-pants kind of guy. He's a lifer who's had to watch the wartime draft bring all kinds of guys into the service who he, possibly, can't stand."

Guyer says his job in the show, with Cullen, is to help ground the narrative in enough wartime reality so that the love story can have its full impact.

As a writer, Guyer, who moved to New York to study acting in the 1970s, has had to think a lot about how to shape stories. His plays include Eden Court, World of Mirth, and Russian Romance. That last piece grew out of time Guyer has spent in both Russia and the former Soviet Union and out of his friendship with Russians. "That play is a comedy about the way Americans project certain images onto Russians that aren't necessarily true. At the end of the play, nobody is quite what he was seen to be at the beginning."

At the moment, Guyer is polishing an older play and is in the middle of work on a new play. "I am a painfully slow writer," he says. "My gestation period is elephantine."

Though he isn't by career a musical-theater guy, Guyer says he never tires of listening to the score of South Pacific waft through backstage during a performance. "I'm always happy to have a 30-piece orchestra in the background. This music gets to you. Even when it's sad it can help pick up your mood." To amplify his point, Guyer -- who is, along with Helmar Augustus Cooper, one of the bookish members of the SP cast -- cites something he recently read by the American author Tobias Wolff.

It's a story called "Flyboys," about a young boy narrator (Wolff's stand-in) and his friend Clark. "At the end of the tale," Guyer says, "the narrator is walking over to his friend's place. His friend has gotten his clothes muddy, and is afraid of what to expect about that from his mother when he gets home."

I'll let Wolff take it from here:

"As we crossed the park [Clark] asked me to have dinner at his place so he wouldn't get skinned alive about his clothes. His dad was still in Portland, he said, as if that explained something. Clark took his time on the walk home, looking in shopwindows and inspecting cars in the lots we passed. When we finally got to the house it was all lit up and music was playing. Even with the windows closed we could hear strains of it from the bottom of the sidewalk.

"Clark stopped. He stood there, listening. "South Pacific," he said. "Good. She's happy."

BRENDAN LEMON is the American theater critic for the Financial Timesand the editor of lemonwade.com.