Masking Exercise

Here is a quotation from Dimitri Tiomkin that could serve to introduce the masking exercise:

To comprehend fully what music does for movies, one should see a picture before the music is added, and again after it has been scored. Not only are all the dramatic effects heightened, but in many instances the faces, voices, and even the personalities of the players are altered by the music.

Source: Dimitri Tiomkin, "Composing for Films," Films in Review 2.9 (1951): 21. (The full article runs pp. 17-22.)