A Full Explanation of the Circle of fifths and How to Use it in Music

Why a Circle?

First of all, what is the circle of fifths and why is it even referred to as a circle?  Let me start out by saying that the circle of fifths by definition is referred to as a geometrical representation of the 12 different pitches in music as they are referred to by the first 7 letters of the alphabet.  The reasons that it's referred to as a circle is because it is cyclical and therefore circular.  Sit down at a keyboard and press any note as you count from one to twelve.  After twelve, you'll arrive at the same note you started on.

As you look at the circle of fifths, you'll notice that the letters are not in alphabetical order.  They actually follow a pattern that is based on major keys of music.  A key of music is a menu of seven different notes in which you draw from to play a song or piece of music.  Major keys of music are differentiated by the lettered sequence of notes and the number of sharps or flats that exist within them.  That's also how they are sequenced within the circle.  

Layout and Pattern

This circle of fifths pattern is based on the first five notes of a key of music.  You can see that the layout of the circle is very much identical to a clock with the exception of letters instead of numbers.  You have C at the very top and as you move clockwise, G is next in the sequence, D follows, etc.  Each Letter is separated by an interval of a fifth. If you break a fifth interval down in it'most basic terms, they're actually notes that are 7 half steps apart.  An easier way to identify fifths is to be familiar with all 12 Major chords.  Look at any two of these notes and they spell out a Major chord without the third in between them.  Just think of power chords which consist of only the root and the fifth.

The Circle of Fifths Reveals Major Keys of Music

Now that we understand the concept of the circle of fifths, how can we actually use it in music?  The most fundamental way it's used is to represent all 12 Major keys of music.  At the very top and center is the key of C Major in which there are no sharp or flat notes in the key.  It's the basis of all Major keys.  If you move to the next key clockwise, you arrive at G Major in which you have one sharp.  Proceed around the circle and each key collects a new sharp until 7 sharps are attained.

But what if you move counter-clockwise?  It actually still moves the interval of a fifth but in the opposite direction.  You're moving a fifth in the other direction but with the same interval. This also begins the keys that have flats in them.  F Major has one flat, B flat Major has two flats, etc.

Just to clarify, if you move clockwise, you're moving through all the keys that have sharps in them.  If you move counterclockwise, you're moving through all the keys that have flats in them.  Something interesting happens at the bottom the circle.  The keys with sharps and flats overlap one another and you have enharmonic keys.  In other words, they have two different names but they're the same notes.  The only difference is: one has flats and the other has sharps.

Representing Sharps and Flats

The Circle of fifths also represent the order of sharps and flats.  You can determine the order of sharps or flats just by looking at the letters on the circle.  Sharps start with an F sharp.  From this perspective, we are not looking at F as the key of F but looking at it from the perspective of sharps.  So our first sharp is F sharp and to find the rest of the sharps simply move clockwise around the circle and you'll find the rest of the order of sharps. C, G, D, A, E, and B.

To find the order of flats, start on the B flat and move counter clockwise to E flat, A flat, D flat, G flat, C flat, and F flat.

Similar Keys   

Now we've established how the circle of fifths map out keys and the order of sharps and flats for us, what else can the circle of fifths teach us about Major keys of music?  One thing it shows us is the similarity of keys.  When you have two keys that are next to each other, they're going to differ by only one sharp or one flat.  That means that all of the other notes are going to be same as the ones in the key next to it.  The only other difference is that their numbering sequence is different.  Understanding the similarity of keys can help you modulate or move from one key to another or write songs with key changes in them so they don't sound abrupt or as if the key change doesn't fit the song you're writing.  In order to find a key of music that is most similar to any other, choose the one to the very right or left of it in the circle.

Very Different Keys

The circle of fifths can also teach us what keys sound the most different from one another.  Let's say that you were interested in an abrupt key change for a dramatic effect in a song or you needed to modulate to a key to give the verse or chorus of a song a different sound.  You may want to find the key that is totally opposite in pitch to the one you're playing in.  Locate the key you're in and look 180 degrees in the circle and you will find the most opposite key.