The Circle of Fifths is a music theory tool used to show the relationship of all the tones of the chromatic scale.
Major Keys
The Circle of Fifths starts at the top, outer side of the circle with the Key of C Major and proceeds to the other major keys. The C Major scale is called a natural scale, meaning it has no sharp (♯) or flat (♭) notes in the scale.
Moving clockwise, the next major key is G Major, the fifth note of the C Major scale (C, D, E, F, G...). Each key after C Major adds a sharp (♯) note within its scale, as the Circle of Fifths continues. The key of G has one sharp (♯) note. The fifth note of the G Major scale is D, and has two sharp (♯) notes in its major scale, and so on.
Reading the Circle of Fifths counterclockwise shows the keys that contain flat notes, the key of F having one flat (♭) note in its scale, B♭ having two flat notes, and so on..
Minor Keys
Minor keys are located inside the circle, starting with the key of A minor. Minor scales are played by starting on the 6th note of a major scale.
In the C major scale, the 6th note is A. A minor is the relative minor key of the C Major key, shown in the circle of fifths. Both the C major and A minor key share the same notes, but are played by starting in different positions of the scale.
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