chord progression
A sequence of chords that forms the harmonic foundation of a piece of music.
In Depth
A chord progression is a series of chords played in succession, creating the harmonic framework over which melodies are built. Some progressions are so common they have names: the I-IV-V-I progression (the basis of countless blues and rock songs), the circle of fifths progression, and the ii-V-I jazz progression. The choice of chord progression fundamentally determines a song's mood and direction. Minor progressions tend to sound darker, major progressions brighter. Certain progressions create a sense of forward motion (I-V), while others create tension (V-IV, the plagal [cadence](/term/plagal%20cadence)). Many hit songs share the same progressions — the I-V-vi-IV pattern (used in Don't Stop Believin', Let It Be, and hundreds of others) has been called the most popular chord progression in pop music.
The four-chord progression I-V-vi-IV is so ubiquitous in pop music that the comedy group Axis of Awesome performed a medley of over 70 hit songs using only these four chords.