Circle of thirds

In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and is a foundational pattern in music. This cycle is expressed through a series of 24 keys and therefore notes. These keys are changed by shifting up or down by a major or minor third. This will lead to a noticeable visual pattern (a circle) and an auditory pattern(interconnected pitches), which are derived from the chromatic scale. Starting from C, the cycle goes as follows: C, Em, G, Bm, D, F♯m, A, C♯m, E, G♯, B, D♯m, F♯/G♭, B♭m, D♭, Fm, A♭, Cm, E♭, Gm, B♭, Dm, F, Am, and back to C.

The circle of thirds is formed by placing the notes of a major or minor scale in order of thirds, instead of in their ascending order of scale degrees. When in a key other than C, the sequence will not start from C, but it will still be in the same overall order when viewed as a circle.