Horizon Theatre is presenting the first Atlanta-produced version of the award-winning musical “Once,” directed by Heidi Cline McKerley, running through March 8.

The show is based on the 2007 film written and directed by John Carney. Then it premiered at New York Theatre Workshop (where “Rent,” among others, began); it opened on Broadway in 2012, won eight Tonys, including Best Musical, and ran until January 2015. The book is by Enda Walsh, music and lyrics by Glen Hansard and Markéta Irglova.

I’d like to say up front that scenic and projection designers Isabel and Moriah Curley-Clay have outdone themselves by transforming the Horizon into an in-the-round theatre and it works brilliantly. One of the theatre’s biggest assets is its intimacy (seating under 200), and now it’s even better. I love it.

Co-Artistic Director Lisa Adler saw the show on Broadway and has been waiting for the chance to bring it to Atlanta and Horizon. Director McKerley says, “At some point in our lives we’ve all felt stopped,” and the two main characters “each start in a place where they feel stuck, and they each find a way to restart their lives.” Sounds good to me; who can’t identify with this situation?

As the audience is taking its seats, “Once” begins before it begins: Nine actor-musicians begin taking the stage, and one jolly fellow simply says, “We’re warming up.” And indeed they do. And you begin to get a hint at the sound and joy and hope that will soon engulf the stage. The audience perks up; everyone is smiling—and we haven’t even started yet.

May I confess at this point that I was a “Once” virgin; had not seen either the film or the musical play. In fact, the only thing I was familiar with was an enchanting song called “Falling Slowly,” which won an Oscar for Best Song. I defy you to forget the music once you hear it.

The scene is Dublin where a wistful young man called Guy (Chase Peacock) leaves his guitar (and his heart) lying in the street. He’s a musician who seems ready to give up his gift. Why? Love gone awry, of course. But he has a guardian angel of sorts: a spunky young woman named Girl (Maggie Salley), who has observed his actions and challenges/inspires him to play again. This particular angel is a Czech immigrant who is herself a singer and a pianist; she seems to have a sixth sense of what ails Guy and determines to give him that necessary boost we all need at times.

“Once” is not an ordinary love story. Guy’s girlfriend left him for New York; Girl has an absent husband who may return. So it’s a strange and wonderful love the two share.

The carefully chosen supporting cast (Sophia Sapronov, Hayden Rowe, Skyler Brown, Paul Glaze, Daniel Burns, Jessica De Maria, Chris Damiano, and Violet Montague) also play instruments, and they are quite marvelous—as actors, singers, and instrumentalists. They are perched in front of you and all over the room: You begin to feel enveloped by music, love, longing, humor—life. It’s hard to describe; you’ll have to experience it. Kudos to Music Director Ed Thrower—he knows his stuff.

Director McKerley has wrapped this gift carefully and with zest and compassion.

Chase Peacock contributes a performance that will win your heart; his singing, acting, and presence are what make matinee idols.

Maggie Salley is a revelation; hitherto unknown to me, she makes Girl fascinating and compelling. She, too, has presence; you can’t take your eyes off her.

The same is true of “Once”; it creates community and seduces you before you know it; don’t miss.

For tickets and information, visit horizontheatre.com.