text: Major thirds cycle The harmonic use of the chromatic third relation originated in the Romantic era and may occur on any structural level, for example in chord progressions or through key changes. The standard Western chromatic scale has twelve equidistant semitones. When arranged according to the circle of fifths, it looks like this:
  Looking above at the marked chords from "Have You Met Miss Jones?", B, G and D are spaced a major third apart. On the circle of fifths it appears as an equilateral triangle:
  By rotating the triangle, all of the thirds cycles can be shown. Note that there are only four unique thirds cycles. This approach can be generalized; different interval cycles will appear as different polygons on the diagram.
  Musical examples
  Tune Up
  These are the first eight bars of the Miles Davis composition "Tune Up". The chord changes are relatively simple, a straightforward application of the ii–V–I progression, which is extremely common in jazz.
  The chord progression is a standard ii7–V7–I progression in D major and then in C major. Assume that the time signature is  and that each ii and V chord gets four beats and the I chord gets eight beats.
  Countdown
  The changes below show Coltrane's substitution of chord changes over "Tune Up". The ii–V–I progression from "Tune Up" still appears but is enhanced with several transition chords that lead to a more complex harmonic progression.