A Dublin street musician (Glen Hansard) meets a Czech immigrant (Marketa Irglova) -- both characters remain unnamed throughout -- who turns out to be a singer herself. They begin spending time together, singing and writing songs, until he leaves for London in hopes of landing a record deal. That's all that happens in Once; it's a low-key glimpse at a few days in these two lives, with very little traditional plot and no attempt to generate artificial drama.
The two lead performances are very good, especially in light of the actors' limited experience; Hansard's only previous movie role was a small part in The Commitments, and this is Irglova's first movie. Hansard has an easy-going rumpled charm, and Irglova (only 17 when the movie was filmed) is irresistibly likable.
The relationship between the two isn't quite a love story -- he makes an awkward pass that's politely, but firmly, turned down -- though the two are clearly attracted to each other. Similarly, the movie's not quite a musical in the traditional sense -- the characters don't burst into song for no good reason -- but there are about a dozen songs scattered throughout the movie, performed by Hansard and Irglova. Some of them are quite good; my favorite of the bunch was "Falling Slowly," which they sing in a piano store where the proprietor lets Irglova practice at lunchtime (she can't afford to buy a piano of her own). The two have fine voices on their own, but the blend of the two is marvelous, and much more interesting than either as a solo.
If you need a lot of plot from your movies, then Once may not be for you; the dramatic highlight, after all, is the recording of a demo tape. But it's got strong performances, good music, and a perfect control of tone and mood; it's wistful and romantic, and I loved it.