Music plays a key role in movies, but not always in the same way. Some films are full-on musicals, with characters bursting into song at every chance they get. Some movies are straight-ahead stories that use music in key moments to drive home an emotional point (for example, John Cusack hoisting a boombox above his head to declare his love with the help of Peter Gabriel). But there's a third option that doesn't get used nearly as much: when characters in the straight-ahead movies suddenly burst into song.

Whether they're being sung in a car or performed with other characters, these songs become special moments in the movie because they tend to be so out of character. You don't expect to hear people singing in something that isn't a musical. Because of that, these moments have an element of surprise that makes them that much more compelling. Even if they're being lip-synched or acted out, there's something magical about them. With that in mind, here are some of our favorite musical moments from non-musical movies:

"Tiny Dancer," Almost Famous
Cameron Crowe's ode to coming of age in the classic rock era is still his best film. This sweet scene sums it all up: despite their rock star exterior, the members of Stillwater are willing to blast some Elton John.

"I Am a Man of Constant Sorrow," O Brother, Where Art Thou? Joel and Ethan Coen's modern classic is packed with musical performances and a killer soundtrack, but it's the multiple renditions of "I Am a Man of Constant Sorrow" that really make the film.

"That's How You Know," Enchanted A few years ago, I came home from work to find my roommate watching Enchanted. I made a joke, then joined him, and we watched the entire thing. The film's a sweet live-action riff on Disney classics, and the production of "That's How You Know" is a wonderful scene.

"Peggy Gordon," The Proposition John Hillcoat's dark Western The Proposition features a script and music from Nick Cave, but it's the haunting rendition of the folk song "Peggy Gordon" that really sticks out.