The word "real" is rarely used to describe the musical genre. Typically, a musical is all about heightened emotions - how else could you explain bursting into song at the drop of a hat. "Once" - a small gem of a film about a struggling guitarist who finds love on the streets of Dublin - is a sneak attack: a movie musical disguised as a low budget indie. The guy and girl in the story (named, simply, Guy and Girl) work on the streets - he's a guitarist and she sells flowers. Their relationship leads them to a piano shop where the owner let's her play during lunch. As Guy (Glen Hansard of the band "The Frames") teaches her one of his songs, to which she adds a piano line and harmony, the film is transformed as their emotions soar on his bittersweet lyrics. From then on every note brings us closer to these characters.

You need only look to the Hugh-Drew romantic comedy trifle "Music and Lyrics" to see how quickly this plot can turn to sap. But where that 2007 dud was as glitzy as Hugh's has-been character's 80s pop band, "Once" is filmed in a guerilla hand-held style that's as raw as Guy's throat-scratching ballads. By keeping the action close, writer-director John Carney (also a member of "The Frames") keeps it real too. It's the opposite of those heightened movie musicals but just as moving (if not even more so).

Mr. Hansard is a natural actor with the deep, welling eyes of an artist and, as Girl, a Czech immigrant scraping to get by, Markéta Irglová is sweet without being schmaltzy. The film is almost entirely about these characters but there are a few notable supporting performances, particularly from Mal Whyte as a disinterested sound engineer and Bill Hodnett as Guy's loving father.

Not since "Moulin Rouge" have I seen a film that has truly done something new with the musical genre. But where Baz Luhrmann's 2001 spectacle somehow managed to heighten the genre even further, "Once" takes the complete opposite approach - distilling the musical form down to its barest essence: boy meets girl, boy and girl sing to each other and fall in love. With few exceptions, the actors sing rather than speak, and the music comes from the story, from the moments and the action. Witness the scene on a bus when she tries to find out more about his background or the laugh-out-loud moment when they apply for a bank loan.

Of course, like any musical, this film is only as good as its songs and here "Once" does not disappoint. Mr. Hansard is a deeply talented songwriter with a voice of heart-tearing urgency. Ms. Irglová's petite voice compliments his well (they released an album in 2006 called "The Swell Season"), particularly during their many harmony-filled duets. If anything, I would like to have heard the characters speak more straight dialogue because I wanted to learn more about them. But that's more of a tribute to the movie than a detriment. Regardless, Mr. Hansard and Ms. Irglová make beautiful music together.