Music also helps provide unity and continuity. Music in William Wyler’s The Memphis Belle (1944) provides a fine example. The Memphis Belle follows the missions of a “Flying Fortress” as it participates in a particularly ambitious and dangerous bombing mission over Nazi Germany during World War II. Music provides continuity between scenes and unity for the whole project. The music signifies “appropriate” emotions, becoming dramatic during the bombing scene and return to home base, and soft and contemplative as the film shows wounded airmen and damaged planes. (…) Music also gives narrative cues. The Memphis Belle begins with shots of the England tourists have come to know, with rolling fields and small villages, each with a centuries-old stone church.

But things are not as they seem. The voice-over dramatically announces that this is a “battle front”. We see a montage of bombers hidden in the landscape, from various angles and distances; the music emphasizes each cut with a loud and dramatic tone, as though each shot is meant to drive home the fact that this peaceful English countryside is not the idyll it initially seems to be.

Carl R. Plantinga, Rethoric and Representation in Nonfiction Film, Cambridge University Press, 1997