sequence
A musical pattern repeated at successively higher or lower pitches.
In Depth
A sequence occurs when a melodic or harmonic pattern is repeated at a higher or lower pitch level. If a short phrase starts on C, a sequence might repeat it starting on D, then again on E, creating a sense of escalation or descent. Sequences can be real (exact transposition) or tonal (adjusted to stay within the key).
Sequences are one of the most common developmental techniques in music. They provide a sense of momentum and direction, carrying the music forward through a series of repetitions at different pitch levels. Vivaldi and Handel used sequences extensively, and the circle-of-fifths sequence (moving down by fifths) is one of the most characteristic progressions in Baroque music.
Vivaldi's music relies so heavily on sequences that musicologists sometimes call his compositional technique sewing-machine music — the patterns just keep repeating at new pitch levels.