Final answer:
In music, a shift from major to minor keys often signals a darkening of mood, with dissonant chord progressions building suspense and tension.
Step-by-step explanation:
The change from major to minor often darkens the mood in music, as the major key is generally accepted to suggest order and stability, while the minor key is more chromatic and therefore less stable. Unresolved harmonies and unorthodox chord progressions in a movie can indeed build suspense and effect surprise.
For example, in a film, when the music shifts to a minor key as the protagonist encounters a potentially threatening situation, the audience may experience a heightened sense of danger and unease. The dissonance in the music adds to this tension, creating a powerful emotional response in the listener.