Section 22.1 Modulation
At its simplest, modulation is a change of key that happens within a composition. In popular music, the change of key will often be called a “key change” instead of a “modulation.” Those who study classical music theory typically reserve the term “modulation” for the slower and more subtle change of key that occurs in many classical pieces, although there are similarities between “key change” in popular music and the classical music term “direct modulation,” which we will study later in this chapter.
Here are examples of key changes in popular music.