In “Once Upon a Time,” one of the most sincere and moving films to be released this year, two characters – simply called Guy and Girl – discover their mutual musical abilities in a guitar and piano shop. “See, the first line goes like this, and then the chorus goes, bum, bum, ba, dum,” the Guy explains, as they begin to play a song that swells to unexpected musical heights.

Unlike films with more conventional scripts, this movie does not avoid the initial awkwardness of the characters’ situation, the lovely clumsiness of two people discovering the connection between one another. “Once” is one of the first modern musicals for our generation – a modest movie about true intimacy, one that is not afraid to offer a lacquered, simple version of love. In an era in which movies are becoming increasingly simplistic, escapist fare, “Once” is quietly defiant. Tender, bittersweet indie rock allows the characters to evolve organically, conveying subtlety and emotion left to interpretation. Long after the last note is played, the shifting melancholy of the music allows for a more complex understanding of love in the modern age.

The film accomplishes this quiet and meaningful examination of love through endearing, realistic characters that use music to convey feelings that would be difficult to express in conventional dialogue. The characters may be so realistic because two real musicians actually wrote all the original songs together: Glen Hansard of the Irish rock band the Frames, and Marketa Irglova, a Czech pianist. Hansard plays the Guy, an Irish street singer who repairs Hoovers in his father’s shop, and encounters the Girl, a Czech housecleaner and flower vendor (Irglova), in the street.

Though these characters could have become condescending and cutesy, they are not defined by their temporary struggles, and the film does not romanticize or pity their economic situations. Irglova stands out as a realistic, assertive housecleaner who loves music but must endure overwhelming responsibilities. Filmed around Ireland – mainly in Dublin – the characters play music on buses, in stores and while walking down the street. Both have led difficult lives, but when they sing, they rise above their earthly limitations in a way that only music could allow.