How can you mend a broken heart? With music, according to “Once,” the Tony Award-winning Broadway musical that grew out of a 2007 indie movie put together by a pair of Irish musicians in a band called The Frames that landed at the Sundance Film Festival, became a sleeper hit and won an Academy Award for best original song. “Once” the musical is at Olney Theatre Center through March 17, a quirky kind of romance about two people — Girl and Guy — who fall in love with the transcendent power of music.

“Are they attracted to each other? Absolutely,” observed Malinda Kathleen Reese, 24, who plays Girl, a Czech immigrant living in Dublin, Ireland. “Is there romance there, potentially? Yes, and they can’t ignore that. But what has brought them together is the music.”

Reese can relate to that. The D.C. native started playing piano at age 5, encouraged by her actor parents. “I very quickly was drawn to the sound of the flute, and I begged my parents to get me a flute,” she said.

Reese went to Sidwell Friends and then Vassar, where she thought about studying cognitive science, but ended up with a bachelor of arts degree in drama, partly because “the people who were most interesting to talk to were the drama majors,” and partly because theater had always been such a huge part of her life. “I grew up watching my mom and dad rehearse,” she said. “I was crawling around rehearsal rooms when I was 18 months old, so I sort of fell into it naturally.”

Reese had played classical flute until she was about 12, “but what I really wanted to do was play the Irish flute. That became a huge part of my life.” She joined a group of Irish-music-loving young people under the direction of Silver Spring-based traditional musician Mitch Fanning, performing at Irish pubs and festivals in Montgomery County and beyond, playing music and making friends.

“That’s what Irish music is about,” Reese said. “There’s this baseline of knowledge and training, so you can just walk into a feis and be able to play with people and make that magic happen.”

That magic happens on the Olney Mainstage, beginning a half an hour before “Once” gets underway. A feis (pronounced “fesh”) is an Irish festival, and the “Once” preshow features the cast (Guy and Girl plus a nine-person ensemble that doubles as the orchestra) playing singalong songs that range from the traditional (“Star of the County Down”) to the contemporary (“Still Haven’t Found What I’m Looking For”) and bantering with the audience as they settle into their seats.

“We call it the preshow — most of the cast will be out on the stage doing numbers they’ve been working through,” said Gregory Maheu, 33, who plays Guy and notes that the confines of space make the musical version of “Once” a bit different from the movie. “The movie feels like a two-hander, in a sense: you’ve got these two people, and secondary characters make an appearance. But in the stage play, it is very much an ensemble piece; the secondary characters are fleshed out, due to the fact that everyone is on stage and often playing instruments in all the songs.”

Maheu praises the considerable musical talent that “Once” Director Marcia Milgrom Dodge and Music Director Chris Youstra have brought together to portray the Irish and Czech characters that populate the world of “Once” and perform its celebrated songs. He himself has some heavy lifting to do, musically, playing the role of a burnt-out young busker who is ready to pack in his dream of making music and work at his dad’s vacuum repair shop.

“I would say that I’m a casual guitar player at best,” said Maheu, who grew up in Alexandria, Virginia, and has a bachelor of fine arts in musical theater from Elon University. “When I saw they were having auditions, I started trying to brush up on my skills. There’s a lot of playing.”

Indeed. Each cast member creates a distinct character as well as contributing to a superb collective sound, and despite his modesty, Maheu’s “skills” are impressive. “I didn’t really anticipate the challenge of actually playing in an ensemble with other instrumentalists,” he said, noting that he first picked up a guitar as a teenager. “My parents aren’t theater people, but they love music,” he said. “My mom loves to sing, and my dad is a guitar player, so when I was young, he bought me a bass guitar.”

Maheu isn’t Irish American, but in the play, he does bear a resemblance to Glenn Hansard, who played Guy in the movie version of “Once” — and he has worked hard to recreate Hansard’s distinct North Dublin accent. He said he’s a big fan of both the musician and “Once.” “I’ve always loved the film,” he said. “There’s something about the energy of it, the cinematography of it: that low-budget feel that really captures this really intimate relationship between these two people.”

The relationship that, as Reese warned, is not quite what it seems. A bit like the actor-musician herself, who’s an international YouTube sensation, internet-famous for her “Google Translate Fails” channel where Reese can be found singing well-known musical theater songs that have been put (through Google Translate) into several different languages and then back into English with hilarious results.

Reese understands as well as anyone that things like love and romance can get lost in in translation; she sees the connection between Guy and Girl as ultimately more satisfying and enduring than most. “We encounter people in our lives,” she mused. “We meet them, we engage with them incredibly quickly, and then we never see them again.

“There’s something incredible about having a book that starts being written, has a beginning, a middle and an end — and then that book is closed.”

“Once” runs through March 17 at Olney Theatre Center, 2001 Olney-Sandy Spring Road, Olney. Regular performances begin at 8 p.m. Wednesday through Saturday; 2 p.m. Saturday and Sunday; and 2 p.m. Wednesday, Feb. 27. There will be an audio-described performance for the blind and visually impaired at 8 p.m. Wednesday, Feb. 20 and a sign-interpreted performance at 8 p.m. Thursday, Feb. 28. Audience members who wish to use these services should contact Julie Via, Patron Services Manager (jvia@olneytheatre.org) to confirm. Tickets begin at $42. Discounts available for groups, seniors, military and students. Call 301-924-3400 or visit www.olneytheatre.org.