Chord Progression - Circle Progressions

Circle Progressions

Introducing the ii chord into these progressions emphasises their appeal as constituting elementary forms of circle progression. These, named for the circle of fifths, consist of "adjacent roots in ascending fourth or descending fifth relationship"—for instance, the sequence vi - ii - V - I ascends with each successive chord to one a fourth above the previous. Such a motion, based upon close harmonic relations, offers "undoubtedly the most common and the strongest of all harmonic progressions". The succession of cadences gives an impression of inevitable return to the key-note of the piece.

Short cyclical progressions may be derived by selecting a sequence of chords from the series completing a circle from the tonic through all seven diatonic chords:

• I - IV - viio - iii - vi - ii - V - I (in C major) Circle progression in C major
• I - V - I Circle progression excerpt: I - V - I
• I - IV - V - I Circle progression excerpt: I - IV -V - I

This type of progression was much used by classical composers, who introduced increasingly subtle inflections. Particularly, substitution of major for minor chords giving, for example, I - VI - II - V allowed a more sophisticated chromaticism as well as the possibility of modulation. These harmonic conventions were taken up by American popular entertainers, giving rise to many variations on those harmonic staples of early jazz that have been dubbed the ragtime progression and the stomp progression. All such progressions may be found used sectionally, as for example in the much-used "rhythm changes" of George Gershwin's "I Got Rhythm".