Circle of fifths

In music theory, the circle of fifths is a sequence encompassing all of the notes in the chromatic scale. Starting on any note and repeatedly ascending by the musical interval of a fifth, one will eventually land on the same note, after reaching all of the other notes:

Descending by fifths, and ascending or descending by fourths also works, since motion in one direction by a fourth is equivalent to motion in the opposite direction by a fifth. For this reason the circle of fifths is also known as the circle of fourths.

Moving around the circle of fifths is a common way to modulate.

See also: enharmonic, cadence, sonata form