What does sequence refer to in music?

In music, the concept of sequence specifically refers to the repetition of a melodic idea at a higher or lower pitch. This technique involves taking an established melodic phrase and repeating it transposed to a different pitch level. For example, if you have a melody that begins on the note C, a sequence might involve playing that same melody starting on D, E, or any other note, maintaining the same interval patterns between the notes but shifting the entire phrase up or down in pitch.

This technique is commonly found in various musical genres and styles, and it's particularly effective in developing themes and creating musical interest. By using sequence, composers can build tension, create a sense of momentum, and enhance the emotional impact of their pieces, as the listener recognizes the original melody being reused in new contexts.

The other options highlight different musical concepts but do not define sequence accurately. Variations of rhythmic motifs, harmonic progressions, and techniques of playing in rounds are distinct practices in music composition and performance that do not encapsulate the essence of what a sequence involves.