Which term describes the repetition of a motive in a different voice?

The term that describes the repetition of a motive in a different voice is imitation. Imitation occurs when a musical idea, commonly referred to as a motive or phrase, is restated in another voice or part, maintaining its original melodic shape but often transposed or varied in terms of rhythm or harmony. This technique is a fundamental aspect of counterpoint and is often used to create texture and complexity in music.

In many classical compositions, the use of imitation can be observed in fugues or other polyphonic works, where multiple voices engage in echoing each other's musical phrases. The effectiveness of imitation lies in its ability to blend distinct musical lines while preserving the integrity of the original motive.

While the other choices are related concepts, they do not specifically refer to the repetition of a motive in a different voice. For instance, a canon is a type of imitation that strictly follows a set time interval between the voices but is not just any repetition. Repetition refers more broadly to the reiteration of musical material without emphasizing the aspects of voice or part. A theme is a principal idea in a piece of music but does not denote the specific process of repeating a motive in another voice.