In La La Land, sound isn’t just something that exists in the background. It is woven into the emotional storyline of the film. It guides how we sense the tension between what is real and isn’t. The director Damien Chazelle and composer Justin Hurwitz used sound to show the lines between normal life and achieving your dreams. In the first scene, the cacophony of Los Angeles traffic sound smoothly transitions into the presentation of “Another Day of Sun,” turning traffic frustration into hope. The honk of a horn, car doors opening, and engine roaring are sounds integrated into the song. Over the duration of the movie, these diegetic to non-diegetic sound shifts show the characters changing.
Rather than just relying on post-production, some of the musical numbers, most notably Emma Stone’s performance of “Audition (The Fools Who Dream)”), were performed live on set. You can hear her take a breath, hear her crack, and the unprocessed emotion of the song. Those imperfections add to the scene a fragile sense of realism that feels human. Ambient sound, distant traffic rumble, footsteps, or the hum of a jazz club, keeps the unseen setting of LA at times. Even when the images go into fantasy, the sound keeps us aware of the real world that exists outside the dream.
The piano motif that goes through the entire story, joining together moments of love, loss, and might-have-been. In the final sequence, the orchestration creates the illusion of a dream almost melting away, an existent thing that exists solely through sound. At the moment when the music finally stops and there is silence between Mia and Sebastian, that is intentional and very loud.