The circle progression is a powerful and often used

In chord number talk I to IV is a circle progression. So is ii to V, and iii to vi, and so on. (take a look at this chart for a mapping of chords to intervals in various keys). So if we were to flesh out a full circle progression in a major scale it would look like this:

I — IV — vii° — iii — vi — ii — V — I

As we can see, each new chord is a perfect fourth above the last one, or a perfect fifth below (thank you inversion). Let’s re-do this for a minor scale now. The progression now looks like this:

i — iv — VII — III — VI — ii° — V — i

As an example, in C major the chords would be:

C — F — B° — Em — Am — Dm — G — C

Try playing this right now to get an idea of how the circle progression sounds. This progression is considered to be harmonically very effective. The V naturally wants to fall to the I making the V — I cadence , also known as the ‘Authentic Cadence’, have the strongest sense of finality. So a progression that is a string of authentic cadences pulls you along until you hit bottom at the tonic.

Now consider that you can embellish any or all of the chords to give the progression a different quality. Make them into 7ths, 9ths, sus4ths. Add pedal tones to them.  Try changing up the rhythm, and for that matter, choose your starting point at will. Try C/// — Em7// — Am7// — Dm/// — Gadd9/// and see what I mean. You can adapt the circle progression significantly to suit your needs yet still maintain its harmonic strength. This makes it a great springboard for writing great songs.

Let us start with the property of the circle that lends it its name. If you start at the top of the outer circle at C and move in a clockwise direction the next note offered is G. The more astute of you will immediately notice that G is the fifth of C. Now try this trick again starting at G. Lo and behold we find D, which is of course the fifth of G. This property also applies to the inner circle of Minors.

Click for full scale image.

Now your saying, “So? Is that all it does? I don’t need a chart for that.” Well, this little chart of ascending fifths has even more fantastical properties. For one, it is also a circle of fourths! Ha. That’s right, by moving in the counter-clockwise direction you see what the forth for each note is. This is exactly what should happen when you descend by a fifth in the diatonic scale. You land on the fourth of the root.

What, still not impressed? Need more? Well it also lets you easily transpose. Say you’re playing something in E and you want to play it in G, find the root of each chord you’re playing on the chart and move back 3 notes in the counter-clockwise direction like you did to get to G from E. To give another example: the simple chord pattern of C — F — G is transposed to the key of D by shifting everything 2 spaces clockwise, and we find the new pattern to be D — G — A.

This leads us to another handy trick, and it goes like this, the fouth, the fifth. That is to say the I, the IV, and the V. It is well established that these intervals have a certain harmonious relationship that keeps coming up again and again. These intervals are the basis for the three-chord-trick, and countless turn-arounds have been built from them. The specifics of that harmonious relationship are not the subject of this post, and maybe in the future I’ll write about it, but for now let’s just say that these chordal intervals sound good together. Now if you’ve read the last few paragraphs you may have guessed this trick already. Choose the root of any key and you’ll find the fourth one space counter-clockwise and the fifth one space clockwise to it. Now you can bang out your punk power chords in any key.

So is that all you do with the circle of fifths? Transpose things? Well the circle is a tool primarily for working with relationships between keys, but I find that it can be useful for inspiring chord progressions. While it is not a harmonic tool, chords whose roots are near the chosen key do tend to sound better together. Fishing around in the general area of the key can sometimes lead to novel and good sounding progressions, and break writer’s block.

Other things of note: The circle will tell you how many sharps or flats are in a particular key. Starting from C and moving clockwise we get progressively more sharps in the stated key. So the key of G has one sharp, the key of D has two and so on. Moving counter-clockwise in the same fashion tells you the number of flats. When incorporating modulation into a piece the smoothest transitions will be between keys that are next to each other on the circle. This is because it is organised in such a way that the keys next to each other vary by only one note.

Since the circle maps a relationship between notes, and all 12 notes are represented, then there are bound to be all sorts of patterns in moving about the circle of fifths that are present in music. I encourage you to toodle around and find them. For example this guy has a whole bunch of other fun things you can do with the circle. I hope this has helped to illuminate the meaning and mystery of the circle of fifths.