Circle of Fifths

The circle (cycle, spiral) of fifths is a pattern of relationships between tones in tonal music, represented visually by a circular chart. The 12 chromatic tones (C, C#/Db, D, D#/Eb, E, F, F#/Gb, G, G#/Ab, A, A#/Bb, B) are reordered so as to be seven semitones (or a perfect fifth, P5) apart (C, G, D, A, etc.), and then arranged in a circle something like a clock. The note C natural is centered at 12 o'clock, rising fifths toward sharp notes to the right, and falling fifths toward flat notes to the left. At 5, 6, and 7 o'clock, the tones B/Cb, F#/Gb, and C#/Db overlap due to enharmonic equivalence. Because fifths invert to fourths, jazz theorists sometimes reverse the circle and refer to it as the cycle of fourths. This is only a matter of terminology—the circle still functions identically. A basic form of the circle presents only those tones that can be tonics in standard major key signatures (such as Ab, not G#). A fuller form of the chart adds the tonics of the relative minor keys. (See Figures 1 and 2).

Figure 1Circle of fifths with tone names. Tones also identified as tonics of major keys, key signatures added. Note the overlap of B/Cb, F#/Gb, and C#/Db at the bottom of the circle.

Figure 2Circle of fifths with addition of relative minor tonic names, and number of accidentals required by each key signature. Key signatures displayed are to be read in treble clef, as in Figure 1.

The individual tones can also function as roots of chords as well as tonics of major and minor keys. Thus, the circle is packed with information and implications about hierarchies of tones, chords, and keys in the tonal system. The relationships within the circle are powerful, with wide manifestations. They can affect the order in which performers acquire technical proficiency of their instruments; impact tuning and temperament considerations; be used by composers in contexts as local as harmonic progressions (ascending and descending circle of fifths sequences), and as extensive as tonal plans of movements and entire works; and play a role in music-theoretic analysis.

The role of the circle of fifths in music perception and cognition is a rich field of exploration for researchers in the psychology of music.