A Chord progression is an arrangement of of two or more chords played in a harmonic sequence. The sequence is typically repeated as a verse, chorus, or bridge. Chords in a chord progression are represented by roman numerals, which corresponds to the degree, quality, or inversion of the chord's root in the key the music is in.
If you know and understand how chord progressions work, you'll be well on your way to writing your own songs, and having the insight into playing many songs.
The roman numerals correspond to the degree of the root chord. For example, a I - IV - V (1 - 4 - 5) chord progression in the key of C would be C - F - G. The C chord is the root ( I or 1 ), count up 4 degrees to the F chord, then count up 5 degrees from the root to a G.
Uppercase roman numerals represent a Major chord, while a lowercase roman numeral represents a minor chord.
Here are some of the most common chord progressions in music. I'm sure you'll recognize them, and begin to use them to create your own music!
Heard as early in the work of Mozart, but became popular in the 1950s during the Doo-Wop genre. This progression can be heard in songs like This Magic Moment by the Drifters, Tell Me Wy by The Beatles, and Stand by Me by Ben E. King.
The pop-punk chord progression became popular in the 1990s, but can be found in songs from the 1950s. You can hear this progression in songs like Soul to Squeeze by the Red Hot Chili Peppers, Cryin' by Aerosmith, and Africa by Toto.
The 12-bar blues chord progression is a 12 bar chord loop that uses the I, IV, V interval. You can hear this progression in classics like Johnny B Goode by Chuck Berry, Folsom Prison Blues by Johnny Cash, and Ain't No Sunshine by Bill Withers.
The Andalusian Cadence, or the Descending Flamenco chord progression, can be found in songs like Babe, I'm Gonna Leave You by Led Zeppelin, Maneater by Hall and Oates, and China Girl by David Bowie.