50s progression

The 50s progression is a chord progression and turnaround used in Western popular music. As the name implies, it was common in the 1950s and early '60s and is particularly associated with doo-wop. It has also been called the "Heart and Soul" chords, the "Stand by Me" changes, the doo-wop progression and, according to Mike Aquino and Hank Green, the "ice cream changes". The first song to use the sequence extensively would seem to be Blue Moon, written in 1933 by Richard Rodgers, and first released, with lyrics by Lorenz Hart, in 1934.

The progression, represented in Roman numeral analysis, is: I–vi–IV–V. For example, in C major: C Am F G.

Theory

In Western classical music during the common practice period, chord progressions are used to structure a musical composition. The destination of a chord progression is known as a cadence, or two chords that signify the end or prolongation of a musical phrase. The most conclusive and resolving cadences return to the tonic or I chord; following the circle of fifths, the most suitable chord to precede the I chord is a V chord. This particular cadence, V–I, is known as an authentic cadence. However, since a I–V–I progression is repetitive and skips most of the circle of fifths, it is common practice to precede the dominant chord with a suitable predominant chord, such as a IV chord or a ii chord (in major), in order to maintain interest. In this case, the 50s progression uses a IV chord, resulting in the ubiquitous I–IV–V–I progression. The vi chord before the IV chord in this progression (creating I–vi–IV–V–I) is used as a means to prolong the tonic chord, as the vi or submediant chord is commonly used as a substitute for the tonic chord, and to ease the voice leading of the bass line: in a I–vi–IV–V–I progression (without any chordal inversions) the bass voice descends in major or minor thirds from the I chord to the vi chord to the IV chord.