2 Movie Music Cues (And How They Comment on the Scene)
Movie music can exist inside or outside of the characters' world.
When there is a logical source for the sound (such as when Rhoda plays "Clare de Lune" on the piano in The Bad Seed), this is called diegetic music. It is within the narrative.
Music which characters do not hear or otherwise interact with or has no logically source within the movie is non-diegetic music. For example, in The Bad Seed when Rhoda walks the streets at night, the score plays "Clare de Lune" with an orchestra; this sound is outside of her world. It's not within the narrative.
Today we peruse two examples of diegetic movie music - sound that the characters technically could be aware of- and how it boosts or comments on the plot.
All About Eve (1950)
At that moment, what song does the pianist she's hired for the evening play in the other room? "Stormy Weather" by Harold Arlen. Not only does it reference the bumpy night everyone has had due to Margo's rudeness, the lyrics of this popular torch song (which are not sung in this scene) mirror Margo's feelings. As the lyrics in the song say,"Since my man and I ain't together, keeps raining all the time."
This torn relationship is a central point of the plot.
How to Marry a Millionaire (1953)
In Millionaire, myopic Pola (Marilyn Monroe) thinks eyeglasses make her appear less attractive. She puts them on in the powder room and takes them off to go back to her date in the dining room.
During the powder room scene, listen for a musical cue. It's distant and tinny, it's meant to be music coming from a band in the dining area. What is the band playing while Pola hides her "cheaters" away in her purse ? "I Got a Feelin' You're Foolin'" by Nacio Herb Brown
Many filmmakers make subtle music cues to comment on the scene. Which ones have you noticed?