Circle of fifths

Relationship among tones of the chromatic scale

In music theory, the circle of fifths (sometimes also cycle of fifths) organizes the twelve pitch classes of the chromatic scale in a cycle of ascending perfect fifths. Since the cycle ascends in the opposite direction by perfect fourths, it is sometimes also called the circle of fourths. Starting on a C, the sequence is: C, G, D, A, E, B/C♭, F♯/G♭, C♯/D♭, A♭, E♭, B♭, F, and C. This order places the most closely related key signatures adjacent to one another.

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