Admittedly, I was a little sceptical when I heard that the musical Once was based on a film of the same name. How do you write a musical that’s grounded in a screenplay? But a show with as many Tony Awards under its belt as Once has at least deserved a chance. Not having seen the film, I found myself approaching the piece without prejudice, at least in terms of the script and production choices.

One of the show’s most original and engaging aspects is audience participation. As I found my seat—almost, but not quite, late—a raucous cabaret was in progress onstage. Audience members mingled on the stage, watching a short concert by the actors, all of whom could not only sing but also play an instrument. A similar set-up occurs during the intermission, when audience members are free to wander up and buy drinks onstage, giving the set a highly realistic edge.

It’s hard to say exactly when Once begins. The ritual of dimming lights and actors entering from the wings is dispensed with, and instead those of the audience who are onstage make their way back to their seats in the brightly lit theatre, which never goes fully dark before the action begins. Instead, the performers present a few more songs, which had me nearly in tears even before the play itself had begun.

From there on in, Once is absolute magic. Scenes fold into one another almost imperceptibly and tie in with the music, creating a seamless soundscape that perfectly underscores a play about musicians. The set, designed to look like the interior of an Irish pub, works beautifully in both indoor and outdoor sequences. One moment has the two leads, played by Stuart Ward and Dani de Waal, standing on a platform above the set against the brick wall at the back of the theatre, looking at Dublin from above. The floor of the stage is illuminated by tiny lights, truly conjuring up a city at a distance.

The furniture is kept simple and minimal, consisting only of a chair or a desk where absolutely necessary. This is especially effective when contrasted with the musicians’ instruments: each guitar or accordion is all the more noticeable and attention-grabbing because everything else is so sparse. It’s refreshing to see a Broadway show that doesn’t rely too much on the technology available these days; bells and whistles seem silly when they’re there only for their own sake.

There was no shortage of talent, either. De Waal in the role of Girl, a music-loving Czechoslovakian immigrant and single mother, is absolutely enchanting. She refuses to fall into stereotypes and doesn’t make a big show of flaunting the accent essential to her character. Ward proves a perfect match for de Waal. Neither outshines the other, and both have numerous chances to show off their talents as musicians and actors. Sometimes in musical theatre the performers act when they sing but not when they speak, but I saw no sign of that here.

I know I’m fully engaged in a play when it stops being a show and becomes a story whose outcome I must know. Once grabbed me and refused to let go, and when the final moment happened, I didn’t want to believe it was the end of the story. The end was satisfying, but devastating. I don’t want to spoil it for those who, like me, have yet to see the film, but brace yourselves.