In counterpoint, what is the term for two melodic lines that move in opposite directions?

• A. Parallel motion
• B. Similar motion
• C. Oblique motion
• D. Contrary motion

Answer: (D)

Contrary motion is when two melodic lines move in opposite directions—one rises while the other falls. This kind of movement helps keep the voices sounding independent and reduces the risk of landing on parallel perfect intervals, which are usually avoided in traditional counterpoint.

Parallel motion would have both lines moving the same way, often with the same or matching intervals, which can produce unwanted parallels. Similar motion also moves in the same direction but not necessarily by the same intervals, so it doesn’t enforce the opposite-direction relationship. Oblique motion has one voice stationary while the other moves, so it isn’t opposite-direction movement either.