Having seen this twice on video in the past month, I was actually moved to reviewing this even though it's been out for quite some time. I would usually refrain from reviewing something like this, but I think there are enough people out there who haven't seen the film even though it did win an Oscar (Best Original Song).
Directed by John Carney (the former bassist of The Frames, not the former placekicker for the Atlanta Falcons), "Once" is an endearing piece of cinéma-vérité chronicling a week in the lives of an Irish busker/vacuum cleaner repairman and a working-class Czech immigrant as they meet and record an demo. Shot with two hand-held digital cameras in and around Dublin, Carney uses the urban Irish setting as the fitting backdrop to his contemporary musical. Luckily, in this musical the music is actually produced by musicians within the context of the film sans dance numbers and fantasy sequences. And the music produced is actually good. Written by the film's stars--Glen Hansard (the frontman of The Frames and one of the stars of the outstanding Irish music film "The Commitments") and Marketa Irglova--the music is great, too. Particularly affecting is the Oscar-winner, "Falling Slowly". Performed as an impromptu duet within the context of the film, this is the point at which any doubt as to the veracity of the film washes away, leaving the viewer vulnerable to the beauty of the music.
As for its stars, Glen Hansard and Marketa Irglova are amazing. Their sexually constrained interplay is engrossing when they're not performing. As for when they are performing, there is no denying the electricity they have. Hansard, for one, is amazing, as anyone who has ever seen The Frames live can attest to. And Irglova's solo on the piano in the studio is devastating.
Essentially the film's plot is but a tool to get the music out there. The collaboration, the camaraderie, and the chemistry are what propel the film, but this is not a problem. As often is the case, sometimes the simplest stories are the best ones. This is no exception.