Bobby (Matthew Scott) is surrounded by his “good and crazy” married friends.
Bobby (Matthew Scott) is surrounded by his “good and crazy” married friends.

“Company,” a 1970 musical about a 35-year-old single man and his married friends, should be outdated by now. Marriage is in decline, 35 is the new 25, and the musical motif of the opening number is based on a telephone busy signal. (When was the last time anyone heard one of those?)

What the setup does bring to mind, however, is Facebook. Scrolling through pages of other people’s wedding photos, the single adult is prone to think, “All my friends are married,” even if that’s an exaggeration. In “Company,” however, now at Signature Theatre, they actually are. Bobby (Matthew Scott) is the go-to best friend of five sets of couples, all very different, all eager for him to find a wife and settle down.

“Married friends have always said, ‘Oh, we don’t want you to live your life by yourself, we want you to have someone!’ ” says “Company” director Eric Schaeffer. “They ask me, ‘When are you going to get married?’ The idea is so universal.”

Or is it? In the 43 years since “Company” debuted, marriage has changed. In 1960, 72 percent of American adults were married. Now barely over half are, according to a 2011 survey by the Pew Research Center.

But the show is not exactly about marriage; it’s about commitment. When Bobby’s friends scoff at his social butterfly existence — “To me, a person’s not complete until he’s married,” says the earnest Jenny, played by Erin Driscoll — they’re actually telling him that he needs to let his guard down and some unmitigated trust in.

“Bobby is always observing, always charming, never showing his cards” Schaeffer says. “It’s only when he’s by himself that he asks himself the really hard questions.”

Schaeffer last directed “Company” in 1993, also at Signature. Then, it seemed to him like a ’70s period piece. This time, he steered away from the polyester and tried to make sure the message hit home: This show, he says, is about all of us.

“We wanted it simple, laid bare. We didn’t want it stuck in a time,” he said. “The questions that it makes you ask about yourself, about your friends — they’re not about the ’70s; they’re still relevant.”

The Plot: “Plot” is a problematic term here. “Company” is more a collection of scenes — Bobby hanging out with his married friends and his three casual girlfriends, trying to figure out why anyone would ever show his or her true self to another human being. (Fun fact: When composer Stephen Sondheim wrote “Company,” he’d never been in a long-term relationship.)

Signature Theatre, 4200 Campbell Ave., Arlington; through June 30, $29-$86; 703-820-9771.