At this year’s Grammy Awards, folksinger-songwriter Anaïs Mitchell won the prize for best musical theater album for her Broadway hit “Hadestown.” But she’s not the only female, folk-flavored singer-songwriter who has a hit stage musical. Erin McKeown (pronounced mick-YOAN) collaborated with playwright Quiara Alegría Hudes on “Miss You Like Hell,” which had a successful off-Broadway run at the Public Theater in 2018, followed by productions in Boston, Denver, Baltimore and now the Olney Theatre in Montgomery County.

Beatriz, the play’s protagonist, is an undocumented Mexican living in California, who hasn’t seen her teenage daughter Olivia since she lost custody to the girl’s American father four years ago. When Beatriz shows up unannounced in front of Olivia’s Philadelphia home, she convinces her daughter to jump in a pickup truck for a cross-country trip.

Along the way, mother and daughter wrestle with all their doubts and resentments, while visiting Yellowstone National Park and encountering friendly strangers and threatening law enforcement officers. The songs these characters sing reflect both the Broadway imperative of advancing the story and the folk-music impulse to explore inner feelings.

“From my singer-songwriter experience, I was able to draw a sense of poeticism, of vibes and feelings, to add to the clarity that musical theater demands,” McKeown says, speaking by phone from her home in Western Massachusetts. “It’s important that more musical theater is written by people from outside that world. We bring more looseness, the stock and trade of pop music. Sara Bareilles’s ‘Waitress’ is a good example of what the pop world can contribute.”

McKeown was well prepared for this fusion because she has loved musical theater, folk and pop music since she was a child in Fredericksburg. Her parents would regularly drive to the National Theatre and the Kennedy Center to see such touring productions as “Cats” and “Nine.” At the same time, she was listening to the records of such singer-songwriters as Suzanne Vega and Ani DiFranco. As McKeown gradually realized she was attracted to women, that epiphany provided a glue between the two genres.

“In singer-songwriter music, it’s more about impressions and fluidity,” she explains. “Musical theater is clear about who the singer is: ‘This is who I am.’ For a young person trying to find her identity, that was important. A lot of people like musicals, but they have a special place in the queer community.”

By the time she turned 35 in 2012, McKeown had already released nine albums and had been touring since she graduated from Brown University in 1999. She wanted to get off the album-tour-album-tour treadmill and find a new way of making music. It was then that she got an email from Hudes, via McKeown’s website, saying the playwright was trying to turn one of her plays into a musical. Hudes had really liked McKeown’s “Hundreds of Lions” album; maybe they could work together.

At that point, McKeown didn’t realize Hudes had collaborated with a pre-“Hamilton” Lin-Manuel Miranda on the musical “In the Heights.” But McKeown was fascinated by the script Hudes sent and knew “this was something I had to say yes to.” So the two women, both the same age, went to work on refashioning the script to accommodate songs. It took six years of workshops and rewrites before it opened at the Public Theater.

“I didn’t know how hard it would be to write a musical,” McKeown reflects. “It’s one thing to be a fan of musicals; it’s a whole other thing to try to make one. It’s like a five-dimensional crossword puzzle, because of the way the songs and the book have to interact with each other. You move one thing here, and it changes something over there.”

Though McKeown is credited for music and lyrics, while Hudes is credited for book and lyrics, McKeown says she contributed bits of dialogue and Hudes provided snippets of music as well. One of the biggest challenges for the singer-songwriter was to craft numbers she wouldn’t sing herself. She wouldn’t be able to fix them in the moment when she stood at the mic; they’d have to be part of a “dependable machine that can repeat every night.”

But sometimes McKeown does get a chance to sing them herself. At most of the productions of “Miss You Like Hell,” she chooses one night during the run to give a free concert before an evening performance. (Olney’s sold-out concert will take place Feb. 15 at 5 p.m.) When she did it at Baltimore’s Center Stage last October, she stood alone in the theater’s lobby and sang four songs from the show, as well as nine songs from her solo albums. Hudes was sitting cross-legged on the floor, cheering on her collaborator.

“I do these concerts because I believe that people who like the kind of music I do will find a lot to like in the theater,” McKeown says. “I’m trying to get people who don’t usually go to the theater to go to the theater, and people who don’t usually go to folk clubs to go to folk clubs. Here’s a chance for people to try something new that they might like.”

Miss You Like Hell

Olney Theatre Center, 2001 Olney-Sandy Spring Rd., Olney. 301-924-3400.

Dates: Through March 1.

Prices: $37-$84.