“Company” is enough to make a single person delete their OkCupid profile.

This Stephen Sondheim musical, which plays at the Lyric Stage through Oct. 9, is the story of a single guy called Bobby and his friends, all of whom are married or coupled, along with three of his girlfriends. Three? Bobby’s a commitment-a-phobe, but the wrangling of his coupled friends makes you wonder if he isn’t the smart one.

Directed by Spiro Veloudos and starring John Ambrosino as Bobby, one of the pivotal moments of this mad melange comes when the embittered Joanne, played by North Shore native Leigh Barrett, breaks out with the bilious assault, “The Ladies Who Lunch.”

“It’s the big 11 o’clock number,” says Barrett. “The veneer is starting to crumble and her self-loathing comes through, and you see why Joanne behaves the way she does. I want people to understand that everything she sings about is about herself. It’s usually the case that all the things we hate about other people are really about the things we hate in our selves.”

Barrett is no stranger to Sondheim or “Company,” or even this role.

“He’s such a smart writer. Having already done ‘Company’ a couple of years ago, I have the luxury of exploring a part I’ve already learnt,” she explains. “I can dig deeper into the character, because I don’t have the stress of learning the part. It’s the best: to come to a piece you already know and refine the character.”

The play debuted in the 1970s but remains relevant as the silliest of human dramas — romantic relationships — still plagues us, if not defines our lives.

“This play continues to break ground; the story is universal. What single person doesn’t feel pulled constantly, and each married character in ‘Company’ says ‘Did I make the right decision; is life better with this person?’ Who doesn’t ask that in real life? ‘Company’ explores that thoroughly, and cleverly.”

But at its root, “Company” is about good old existential angst and the human turmoil of always wanting more, and forever questioning whether we are happy, and whether we should be happier. Is Bobby happy?

“Sondheim can seem dark sometimes. I’m not an intrinsically hopeful person, but everyone is always searching for the light. It ends with Bobby singing ‘Being Alive’ and it’s not the kind of song that someone sings before throwing themselves off a bridge,” she reveals. “What he chooses once the curtain comes down, we don’t know. That’s up to the viewer to decide. It’s a really fun ride.”

If you go:

“Company”
Through Oct. 9
The Lyric Stage
140 Claredon St.
From $25, lyricstage.com