Circle of Fifths

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This is a music theory tool which can be used in a wide variety of ways
This short blog shows how to build it.
The illustration below shows a circle set out like a clock.
Around the outside of the circle will be the major keys,
whist on the inside of the circle will be the relative minor key.
This example is blank, with one exception.
As the intention is to show how it will be populated, using the C major scale.
I used a simple technique to actually write one out. It was something
I had to know to do in my music theory and classical guitar exams.
The way it works is scales which contain sharp notes go round the clock clockwise.
Scales with flat notes go round the clock in an anti clockwise direction.
The illustration below shows a clock and at the 12 O clock position
you place the C note.

 To get the first sharp scale note. We run through the notes of the C major scale.
Which are C D E F G A B and find the fifth note which is the G..
The G note will be placed at the one o’clock position.
Playing through a G scale will be found one sharp note which is the F#.

To find the next key we go through the G major scale notes.
Which are G A B C D E F and find the fifth note which is the D.
This will be placed at the two o’clock position.
Running through this scale we find two sharp notes which are the F# and C#.
Continue in this way round the circle till you have the 7 sharp keys.

The notes inside the clock are as stated the natural minor to the
key show on the outside of the clock face.
To find these simply go to the c major scale above and find the 6th note which is the A minor.
To find the The natural minor of G find the 6th note which is the E minor.

The illustration below continues the circle, as an exercise using the above examples above.
Try to find the relative minor of the A scale

To find the flat keys the process is reversed. Using this direction it is
called the Circle of Fourths.

You build the sequence going anti clockwise from 12 11 10 etc.
To find these keys, we start at the C scale at 12 o’clock. Using the same 
notes which are C D E F G A B.
But this time we are looking for the fourth note in the scale which is the F.
We place the F note at the 11 o’clock position.
Run through the F scale we find one flat note which is the Bb.
To find the key at 10 o’clock simply run through the F scale, which is F G A B C D E.
Finding the fourth note which is Bb. and add that note to the ten o’clock position.
Running through the  F scale we find the two flattened notes are the Bb and Eb.
Continue all the way round till you have the 7 flat keys


The notes inside the clock are as stated the natural minor to the
key show on the outside of the clock face.
To find these simply go to the c major scale above and find the 6th note which is the A minor.
To find the The natural minor of Bb find the 6th note which is the D minor.

The illustration below continues the circle, as an exercise using the above examples above.
Try to find the relative minor of the Eb scale

This is the basic method used to populate the clock. Things start to get interesting when
you get further round to the point where the sharp and flat keys converge.
But that is the subject for the second blog in this series.

Hopefully this provides a spot of insight into the circle of 5ths and 4ths.
Stay well and enjoy your playing.
All the best
Mark Reed