The document discusses different classifications and uses of sound in motion pictures. It covers synchronous vs. nonsynchronous sound, diegetic vs. nondiegetic sound, and how music and sound effects are used to shape the narrative and themes of a film. Musicians and sound designers work with the director from early stages to create a cohesive soundtrack. Sound can be recorded during filming or later added, and it can come from within or outside the world depicted on screen. The history of sound in films is also summarized, from early talkies to innovations by directors like Eisenstein and Welles in using sound montage. Music is discussed in terms of mood, location, and characterization suggestions, as well as how it can control or contrast emotional shifts