Which term indicates that music should return to the original tempo?

The term that indicates music should return to the original tempo is "A tempo." This instruction is commonly used in musical scores to signify that the performer should revert back to the initial speed of the piece after a section that may have altered the tempo, such as a ritardando or a tempo rubato.

Understanding tempo is crucial in music performance, as it affects the pacing and emotional delivery of a piece. "A tempo" acts as a clear signal to the musician that it is time to go back to the established rhythm that was set at the beginning, ensuring that the flow of the music is maintained.

In contrast, the other terms serve different functions in music. "Ritard" indicates a gradual slowing down, "crescendo" refers to a gradual increase in volume, and "tenuto" suggests that a note should be held for its full value or slightly longer. These terms indicate specific alterations to performance rather than a return to the original tempo.