Voices moving in the same direction by the same interval is which type of motion?

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

Answer: (B)

Moving two voices in the same direction by the same interval keeps the distance between them constant, which is parallel motion. For example, if soprano and alto start a fifth apart (C and G) and both rise by a step (to D and A), they still form a fifth—the interval hasn't changed. In traditional harmony, parallel motion is generally avoided when it creates consecutive perfect intervals like fifths or octaves, because it reduces voice independence.

In other types, contrary motion means voices move in opposite directions, oblique motion means one voice stays while the other moves, and melodic motion refers to the movement of a single line rather than two voices.