From Claudia Gorbman’s “Unheard Melodies: Narrative Film Music”. 1987, Indiana University Press.

I. ‘Invisibility’: The technical apparatus of nondiegetic film music must not be visible.

II. ‘Inaudibility’: Music is not meant to be heard consciously. As such it should subordinate itself to dialogue, to visuals – i.e., to the primary vehicle of the narrative.

III. Signifier of emotion : Soundtrack music may set specific moods and emphasize particular emotions suggested in the narrative, but first and foremost is a signifier of emotion itself.

IV. Narrative cueing:

• Referential / narrative: music gives referential and narrative cues, e.g., indicating point of view, supplying formal demarcations, and establishing setting and characters.
• Connotative: music ‘interprets’ and ‘illustrates’ narrative events.

V. Continuity: music provides formal and rhythmic continuity – between shots, in transitions between scenes, by filling ‘gaps’.

VI. Unity: via repetition and variation of musical material and instrumentation, music aids in the construction of formal and narrative unity.

VII. A given score may violate any of the principles above, providing the violation is at the service ot the other principles.

Cheers,

Alain