16th February 2021
First of all I want to clear up some possible confusion that often arises when talking about the Circle of 5th’s. If you go backwards round the circle, you can get a Circle of 4th’s.
Now don’t worry about that too much at this stage, but just be aware of the two names for the same circle. Both the terms Circle of 5th’s and Circle of 4th’s are correct theoretically and it just depends on what way round the circle you are going.
The term ‘Circle of 4ths’ tends to be used more in Jazz analysis.
Circle of 5th's
So What is the ‘Circle of 5th’s’?
Well it is a circle that is drawn to illustrate the relationship that notes have to each other. The 12 notes of the chromatic scale are organised in a circle, as a sequence of perfect 5th’s.
Moving Round the Circle
Look at the top right of the diagram, and you will spot C on the outer circle. If we move round the circle to the right, you will see G next on the outer circle. G is a 5th above C. Then if we go up a 5th from G, we get D, and it continues like this round the circle. This side of the circle has all the sharp keys.
You can go the other way round the circle and instead of going up a 5th, go down a 5th. F is down a 5th from C. Bb is a 5th down from F. The B is flat because B’s are flat in F major. The circle then continues round in that direction.
Circle of 4th's
Now at the beginning of the article you might remember me saying that this circle can also be called the Circle of 4th’s. That is because when you turn a perfect 5th upside down you get a perfect 4th. For example, if you go down to F from C (the first two notes anti-clockwise round the circle), you are going down a 5th. BUT if you go up to F from C, you are going up a 4th.
If this is all too confusing at the moment, then just work in 5th’s for now and don’t worry about the Circle of 4th’s.
Relative Minor Keys
The letters around the outer circle represent all the major keys. Now if you look in the inner circle, you will see all the minor keys.
Minor keys are related to major keys and each minor key has a relative major key. This means that they share the same key signatures and chords.
These minor keys in the inner circle also go round in 5ths, the same way as the outer circle and from the circle you can also see what it’s relative major key is.
A minor’s relative major is C major, F minor’s relative major is Ab major, F# minor’s relative major is A major, and so on.
It is useful knowing what key a piece of music is in because then you know what common chords you are likely to see. A major key and it’s relative minor will share the same common chords.
Another great thing about the circle of 5ths diagram is that all the common chords of one key are in one quarter segment of the circle. So the common chords for C major are , C, Dm, Em, F, G, and Am and you can see all those chords in the top quarter of the circle. The common chords in Am are Am, C, Dm, Em, F, and G and again they are all in that top quarter.
This works for any key. the common chords for A major are, A, Bm, C#m, D, E, and F#m. The relative minor to A major is F#m who’s common chords are F#m, A, Bm, C#m, D, E and F#m. Again you can find these six chords in a segment on the right hand side of the circle.
The Circle of 5th has so much music theory contains within it, and I have only scratched the surface in this article. You sometimes find a third circle that contains the sharps and flats that you will find in each key. This can be really useful too.
For now I suggest getting to grips with the contents of this article and then further studying the circle yourself. Try for example to find some other common chord progressions in certain segments of the circle.
Today we have looked at some of the most important foundational elements of music theory, and this knowledge will go a long way in helping to understand how music is constructed.