The Circle of Fifths

The Circle of Fifths is a fascinating representation of musical notes. This lesson shows how it can help you construct major scales.

Constructing the Circle

To construct the Circle of Fifths, take a given note - let’s use C for this example.

Then take the note a perfect fifth above C - counting seven semitones gives us G.

Then take the note a perfect fifth from G. This gives us D.

Repeat this process until you get back to C. The result should look like this:

(You might wonder why I use flats on the left side instead of sharps; I’ll answer that in a second).

In broad terms, the key signature of a scale refers to the flats/sharps in the scale, which help identify it. The circle of fifths helps deduce the key signatures of all the scales it contains. Don’t believe me?

Going clockwise

Take a look at the top of the circle: C. The C Major scale contains 0 sharps and 0 flats, as we found in the previous lesson. You can construct the scale yourself to verify.

Going clockwise, the next one is G. G Major contains 1 sharp - F#. Next is D Major, with two sharps: F# and C#. See the pattern?

Fast-forward to Db/C#. This is the scale with the most sharps - F#, C#, G#, D#, A#, E# and B# (going in order from F). That brings us to Ab. We would expect this scale to have 8 sharps, one more than C#. But constructing the scale that way (using G# instead of Ab) leads to this:

G# - A# - B# - C# - D# - E# - F## - G#

Notice the double-sharp on F - this is the same note as G. Using Ab instead of G# allows us to write a much neater version of the scale:

Ab - Bb - C - Db - Eb - F - G - Ab

The same logic applies to all the flatted notes on the left-half of the scale. In fact, a similar pattern emerges on this side as well.

Going counter-clockwise

Starting from C again, but going counter-clockwise: the first note we see is F. This has one flat - Bb. Next is Bb itself, with two flats: Bb and Eb. This is followed by Eb with three flats - Bb, Eb and Ab. This continues down to B (AKA Cb) with seven flats - Bb, Eb, Ab, Db, Gb, Cb and Fb.

The circle of fifths can deduce which notes are sharped/flatted in a major scale. The number of positions between _C_ and the scale in question gives the number of sharped/flatted notes. The direction indicates if they are sharped or flatted (left of C = flatted, right of C = sharped).

Assume there are n sharped/flatted notes. If they are sharped, the first n notes going clockwise from F will be sharped. If they are flatted, the first n notes going counter-clockwise from B will be flatted.

Fat Cats Go Down Alleys Eating Burgers

This is a fun acronym that my high school Music Theory teacher used to remember a condensed version of the circle of fifths. It works very similarly to the circle - count up from C to the scale that you’re constructing. Going to the right added sharps (starting from F#) and going to the left added flats (starting from Bb). The difference is that wrapping around the right (going from B to F) adds a sharp (the F becomes an F#). Wrapping around the left (from F to B) added a flat (B to Bb). So, if you wanted to construct F Major, you would go 1 spot to the left. To construct F# Major, you would go 6 spots to the right (5 up to B, then wrap around to F#).

This method is much easier to remember and works well for me, but your experience may vary.