“I was never into women’s lib, and I’m not an activist in any way,” Ms. Bass said. “But I do think the audience sees it in a different way. They look at it as such an accomplishment for women.”

Ms. Colella, 42, discovered a love for singing as a child, first with her mother at home, and then in a Presbyterian church. She spent time as a rock singer (while working at an insurance company call center) and was doing stand-up comedy in Los Angeles when in 2003 she was cast in her first Broadway show, “Urban Cowboy”; she has since had roles in “High Fidelity,” “Chaplin” and, her longest-running, “If/Then.”

“It’s kind of become a joke that a lot of the shows I have been in have closed very quickly,” she said. “This is the first time I’ve been in a genuine hit.”

She developed her characterization of Ms. Bass before she met her, based on reading interview transcripts and watching a television interview. They met in 2015 when Ms. Bass showed up for the opening of the show’s first run, at the La Jolla Playhouse, and, Ms. Colella said, “We just embraced like we were long-lost pals.”

That performance was difficult for both of them. “My husband and I were in tears, and we missed 75 percent of the show,” Ms. Bass said. Ms. Colella found watching Ms. Bass’s emotional response challenging. “Her hands were over her face, and she was sobbing openly,” she said. “I’m not a robot — I could feel something inside of me start to break. And yet, I have a job — she remained stoic through those five days, and I’m in those five days.”

The two have their differences. Ms. Bass, a Florida native who has lived for decades in Texas, is a married mother of two; Ms. Colella, a South Carolina native who lives in New York, describes herself as “mostly gay” and is in a polyamorous relationship. (“I don’t believe in hiding any part of myself,” she said. “It doesn’t feel authentic.”)