There are many examples of beautiful works of musical art that fall through the cracks of the mainstream perspective. The soundtrack to the independent film “Once” is a prime example. However, this album won an Academy Award for Best Original Song and was nominated for two Grammy awards. Although it’s still not known in the mainstream, the fact that it won such honors is a good sign.

The film starred Glen Hansard (of the Irish band The Frames) and Markéta Irglová. They are also the main contributors to the soundtrack. The majority of the songs feature both artists singing with a chemistry that isn’t often found between collaborators. Most of these songs were performed either by The Frames or Irglová and Hansard on an album before the movie. The music takes a simple front, but the ­effect is a subtle and beautiful complexity.

The soundtrack opens with the award-winning song “Falling Slowly,” with bittersweet yet hopeful strains. These feelings permeate most of the disk. The rising and falling instrumentation match Hansard and Irglová’s vocals. The strength and confidence of Hansard’s voice meets with ­Irglová’s fragility to make a wonderful contrast. Many of the gems of this album (“If You Want Me,” “The Hill,” and “Once”) feature these elements.

The warmth and bittersweet aching quality of this album is apparent even in songs not performed by Irglová and Hansard. There is really only one song that might seem different to ­listeners. “Broken Hearted Hoover Fixer Sucker Guy” has the potential to be distracting when not in the context of the film. However, this doesn’t detract from the overall charm. This is still one of the most consistently well executed albums of the past few years.