top of page
  • rbedwell3

The use of the circle of fifths in Jazz


I don’t think it is well known, and if I am wrong please forgive me, but when improvising over a chord in a jazz idiom, the circle of fifths is used almost all of the time. Hear me out.

Take a Major chord, let’s say C Major. Not part of a progression, but just a simple Major 7 chord. The go to mode is C Lydian, mode IV of G Major. That is a circle of fifths substitution. Go forward in the circle of fifths and play the mode on C, Lydian.

NB: I use the Marl font as a shorthand for these changes, but that is not possible in this format so I’ll continue to write this in longhand.

Lets look next at playing over a minor chord. Take A minor, the jazz approach is to play A Dorian. Again, a mode from the G Major scale. So, go forward in the circle of fifths and play the mode on A. Can you see how the use of the circle of fifths is implicitly used in the jazz genre?

What about playing over a non-resolving dominant chord? Well obviously Mixolydian is common, so G7 would have G Mixolydian played over it, so no circle of fifths substitution there. But wait, what about the more sophisticated choice of G Lydian Dominant? That is mode IV of D Melodic. This is where the circle of fifths substitutions become a little more interesting. To get D Melodic, move back through the circle of fifths, C Major to F Major and then the Melodic is on the relative minor, so in shorthand: Back - relative Melodic.

This is actually a mathematical process, as are all of the modal substitutions mentioned so far, but it is too big a subject for a facebook post, so I’ll leave the more intrigued readers to check out my group https://www.facebook.com/groups/modalmethodmusictheoryand my book Modal Method here: https://www.bedwellmusic.co.uk/general-7

Now, lets take a cadence, say a ii/V/i in C minor. The chords are Dminb5 – G7alt – C minor. The obvious choice is to use D Aeolianb5/Locrian nat2 over D minorb5 followed by G Alt/Superlocrian over G7alt. D Aeolian b5 is mode VI of F Melodic, so the circle of fifths move is back a fifth and then substitute F Melodic for F Major, or another way of saying it is: back a fifth and then parallel minor using Melodic, or: back – parallel Melodic. ( A two part move.) See additional note in comments.

G Alt/Superlocrian over G7 is as follows: G Altered/Superlocrian is mode VII of the Ab Melodic scale. How do we get there? Well the answer is: From F Melodic, the relative Major is Ab, and the Melodic scale is played upon that root, so that's F melodic -Relative Melodic.

Some of you may be thinking, ‘but so what, I know how to use these modes over these changes already’. That is true, but understanding the mechanics of why these changes work will unlock the door to exploring more unusual choices over such changes as well as highlighting the underlying processes that are occurring in jazz as well as other genres of music. Believe it or not, these approaches occur in baroque music also, it is not unique to the jazz idiom.

This brings me to the next step in our understanding of how modes work in music, explicitly or implicitly, with the dawning realization that what we are looking at are algorithms, complex moves akin to solving a Rubik’s cube. But more on that at a later date. As you can probably tell, I have a mathematical way of thinking when it comes to music and it has brought to light many aspects of music that are unexplored. I hope you enjoy the journey. See my other posts for more on music and maths.

This short extract is part of a larger chapter on the implied use of the circle of fifths in jazz. It is not available as yet but will be added to the second edition of the Modal Method at a later date. If you consider this post worth sharing, please consider subscribing to my facebook group too.


3 views0 comments

Comments


bottom of page