Circle of Fifths – The Scales (Part 1 – Addendum)

Holy Crap, I forgot a very important point in the last article! If you’ve read Part 1, then you already know that if you shift the numbers around the circle, you get the scale for whatever the 1 is on. However, the shift follows some interesting rules that allow you to determine how it’s going to change. Looking at our example scale of G major, we can see that shifting the numbers 1 position to the right gives us this:

Gmaj shifted clockwise to Dmaj

Gmaj shifted clockwise to Dmaj

Given we already know the 6 notes from the Gmaj scale will still be in the Dmaj scale (the CoF says they will be), then we only have to figure out the missing two. And given the “2/9” note is the same in both positions, we know that the blue “?” will be “E”. So what will the green “?” be? Well, the rule is that when shifting clockwise, whatever was the 4th  in the previous scale get’s sharped and becomes the 7th in the new scale! So, given that rule, the 7th position value must be C#. That means that our scale for Dmaj is:
D  E  F#  G  A  B  C#

Now looking at our original Circle of Fifths reference image, we know that the Dmaj scale has 2 sharps, so that’s correct. And looking at the bottom part of the reference image we’ll see that the new scale that we determined based upon the rules of shifting clockwise gave us exactly the correct scale! And we didn’t even have to look back at our reference image at all!!!!

“But what about the other direction, counter-clockwise?”, you ask (or perhaps “anti-clockwise” from across the pond).  Well, that’s exactly the reverse. Let’s look at it:

Gmaj shifted counterclockwise to Cmaj

Gmaj shifted counterclockwise to Cmaj

Again, we can discount the 2/9, as in this case it will be D. So now we just need to know what the 4th will be. In the CCW shift, you’ll simply flat the 7th from the Gmaj scale, making it an “F”. That means that the Cmaj scale is this:
C  D  E  F  G  A  B

And we know that the Cmaj scale has no sharps or flats, so were good! It’s that simple.

Ok, now for the minor Scale. It’s very much the same thing. Here’s the clockwise shift for the Em scale:

Em clockwise shift to Bm

Em clockwise shift to Bm

In this case, we know that 4th position will be E, so that’s done. For the 2/9, it’s simply the same as earlier except we’re going to sharp the 6th position, making the 2/9 a C#. That makes the Bm scale this:

B  C#  D  E  F#  G  A

And if we do similarly for the couterclockwise shift of the Em scale, we get this:

Em couterclockwise shift to Am

Em couterclockwise shift to Am

Which makes the 4th another D and the 6th becomes a flatted F#, or F.

And that’s it. In summary, you now should understand that if you:

  • shift a Major scale one position toward it’s 5th (clockwise), then the scale only changes by one note, and that note is going to be the original scale’s 4th sharped.
  • shift a Major scale one position toward it’s 4th (counterclockwise), then the scale only changes by one note and that note is the original scale’s 7th flatted.
  • shift a Minor scale one position toward it’s 5th (clockwise), then the scale only changes by one note, and that note is going to be the original scale’s 6th sharped.
  • shift a Minor scale one position toward it’s 4th (counterclockwise), then the scale only changes by one note and that note is the original scale’s 2/9 flatted.

I hope that’s helpful, and sorry for the omission from the original Part 1. It’s probably just as well, as this is a lot to absorb.

Next up: Chord Construction.

One Response to “Circle of Fifths – The Scales (Part 1 – Addendum)”

  1. […] please see the Addendum to this article! There is additional information about this that I’d […]

Leave a Reply