The circle of fifths shows the relationship between the 12 tones of the chromatic scale and their corresponding key signatures and associated major and minor keys.
To the guitarist, it serves as a useful tool for identifying I, IV, V chord progressions in any key, finding relative minor chords – and if you’re able to sight-read – a speedy way to know exactly what all those sharps and flats mean. It’s also very helpful for songwriting.
Here’s what we’ll cover:
Deciphering the Circle
First of all, there are three important bits of information:
- the outer ring shows the actual key signatures (i.e. how many sharps and flats it has)
- the middle ring (the capital letters) represent the corresponding major keys
- the inner ring (the lowercase letters) represent the corresponding minor keys
Like an analog clock, it’s divided into 12 points, but instead of numbers, there are letters. While the numbers on a clock represent the hours of the day, the letters on the circle of fifths represent the prominent major and minor key signatures in western music.
Going around it clockwise, you get perfect 5ths (forming the circle of fifths). If you move around it counterclockwise, you get 4ths, or what is known as ‘the circle of fourths’.
Taking the key of C as an example…
G is a 5th up from C
D is a 5th up from G
A is a 5th up from D
E is a 5th up from A
and so on…
The same applies to the minor keys (on the inner ring). Let’s start with A Minor.
E is a 5th up from A
B is a 5th up from E
F# is a 5th up from B
C# is a 5th up from F#
If you go round counterclockwise it works in the same way as above, only going counterclockwise gets you fourths.
Sharps and Flats
As you go from C, to G, to D, to A, etc… the number of sharps in the key also increases by one. Like a clock, that’s one sharp per hour. Until you reach 8pm. At this time, if you start looking at the clock backwards, and count from 1 to 4 where you’d normally see the numbers 11 to 8, you will see that the amount of flats per key coincides with the ‘time’.
How to Use It
Finding ‘I IV V’ In Different Keys (Modulation)
Using the circle of fifths makes what’s called ‘modulating’ from one key to another much easier. That’s because the keys to the left and right of the key you’re in are always considered the best options when modulating.
Just pick three notes at any time, for example, take C – to its left F (that’s C’s fourth), and – to its right G (that’s C’s fifth). That gives you first, fourth and fifth, pretty much the most common chord progression in rock and pop music!
You can, of course, embellish this to get something more original. But it’s a great starting point, and always sounds good.
Finding Relative Minor
Another songwriters trick is switching from a major key to its relative minor. You can do this by going from the middle layer of the circle to the inner layer. This can make for a cool bridge/middle 8, which has a different ‘feel’ to the rest of the song.
Thinking about music in a theoretical or mathematical way encourages a deeper understanding of your craft and will lead to more satisfaction in your musical experiences.
Not only will it enable you to – on-demand – do things like key changes, shifts to relative minors and speedy sight-reading, but it will make you think about the gaps between notes and why and how they invoke different moods and vibes.
If you’re a musician who reads sheet music, this information is invaluable when it comes to reading and learning pieces, and if you’re a songwriter this will speed your process up and ensure that you don’t get stuck for ideas.
If you don’t read music, but would like to learn songs more quickly and understand why the songs work, this circle has your answers. You’ll start to see that the songs you are playing really do have the number of sharps/flats that match with the key that your starting chord was on, very often. Our ears have developed to become pleased by certain intervals, and artists who aim to be listenable write in a way which pleases the ear.
However you use the circle, it is sure to treat you well and guarantees several ‘aha’ moments as you go round and round.