Progression
the act of progressing, advancing, or moving forward; progress, advance. In In mathematics, mathe regual advance by increase lar or proportional p advance or decrease of numbers. A series in which the terms increase or decrease according to a uniform law. There are two kinds of progressions, arithmetical and geometrical. In music, there are two kinds of progression, melodic and harmonic. The former is a succession of sounds forming a tune or melody, but the term is also applied to an imitative succession of melodic phrases, that is, to a melodic sequence. Harmonic progression is the movement of one chord to another, and is diatonic or chromatic.
The term is also sometimes used as synonymous with sequence.