Diegetic Music in Baby Driver

In the film Baby Driver, music is used in harmony with a multitude of scenes in the film, with the music often being in time with actions, incidents and events going on in the scene, most notably in the iconic driving/car chase scenes, which feature the main character 'Baby' as the getaway driver for a group of criminals he is associated with.

These scenes come with a unique feature, as the music is furthermore tailored to the scene, with the main protagonist of the film, 'Baby' listening to the music within the film on his headphones, which the audience can hear as non-diegetic music as part of the soundtrack. However, it is what 'Baby' can actually hear throughout the scene when he is listening to the music with his headphones, which the audience too can hear. Technically, the way in which the music is used is non-diegetic, however it is diegetic to the character 'Baby' and nobody else can hear it except him.