A chord progression (also chord sequence and harmonic progression or sequence), as its name implies, is a series of chords played in order. Chord progressions are central to most modern European-influenced music and the principal study of harmony. Compare to a simultaneity succession. A chord change is a movement from one chord to another and may be thought of as either the most basic chord progression or as a portion of longer chord progressions which involve more than two chords (see shift of level).

Generally, successive chords in a chord progression share some notes, which provides harmonic and linear (voice leading) continuity to a passage. In the common-practice period, chord progressions are usually associated with a scale and the notes of each chord are usually taken from that scale (or its modally-mixed universe).