I am learning about the modes, relative scales, and the circle of fifths. I am interested in adding key changes to my playing.

I understand that if you're playing in, say C major, the easiest key changes to make are to the immediate right and left on the circle of fifths. That would be, to G major (a more common, "rising" key change) or to F major (a jazzier, "falling" key change). I also understand the gist of mode relativity. That is, C major is equivalent in note makeup to E Phyrgian etc.

So say I'm in E Phrygian and I'm looking to change keys. Could I use the following logic to select my next key?

1) E Phrygian = C Major

2) G Major is a nice key to change to from C Major

3) G Major is relative to E Aeolian and A Dorian

4) Therefore, I could easily change keys to E Aeolian or A Dorian

I am grateful for your help. I appreciate any resources for learning more about these topics, but I am especially curious to hear if this sort of logic checks out. For reference, here is that circle I have been talking about: enter image description here

  • 1
    I've always considered C>F 'key change' as 'rising', while C>G 'key change' as falling. Somewhat subjective. Probably on the basis that C>F is a fourth up, while C>G is a fourth down.
    – Tim
    May 17, 2018 at 7:34
  • Why do you choose fourths over fifths? On my guitar C to F would be up at fifth and C to G will be down a fifth. May 17, 2018 at 12:09
  • There's just too many ways to look at this, I see C to F as up a fourth and C to G as up a fifth, as long as we're talking about the same octave. That's just the way I learned my Alphabet starting at A and moving forward from that point. May 17, 2018 at 14:37

6 Answers 6


You're confusing keys with the modes of a key. And you're confusing what is 'easy' to do with what is interesting to do. 'Easy' can be bland.

Yes, if you're in C major (or one of its modes) it's easy to slip into G major or F major (or one of their modes). But those are 'easy' modulations, not interesting ones. And if it's a song, a shift of a 5th up or down will very likely take it out of the vocalist's comfortable range.

I suggest you don't try to construct music from 'theory'. Concentrate on reading and playing lots of repertoire. See what good composers and songwriters have done already.

The 'circle of 5ths' isn't all that much use anyway. It's a pretty diagram which fills a page in a theory textbook. But all it really tells us is that any chord can be used as the dominant of one a 5th lower/4th higher. True, but trivial.

  • 1
    Thanks, Lawrence! I am interested in approaching music this way not to create any particular type of music (interesting, vocal, or otherwise). Just out of an interest in algorithms and music... not in some quest to skip learning theory or repertoire. Anyway, I am not sure this answers my question, unless my confusion between keys and the modes of a key make the rest of what I say nonsense. Which I don’t doubt could be the case :) May 17, 2018 at 4:29
  • I do think I get what you are saying though. Here is another way to phrase what I’m still wondering about: If I were to take the circle of 5ths (interpreting them as scales rather than keys) and replace the major scales with, say, the relative Dorian equivalent, what would be the use of that circle? May 17, 2018 at 4:35
  • Good question! I'd answer it by saying that the 'circle of 5ths' isn't all that much use anyway. It's pretty, and it fills a page in a theory textbook. But all it really tells us is that any chord can be used as the dominant of one a 5th lower/4th higher. True, but trivial.
    – Laurence
    May 17, 2018 at 16:32

The circle of fifths is showing us what keys are most closely related. Keys that are adjacent have all but one note in common. This means that modulating from one key to an adjacent one will have a smooth transition more easily than less closely related keys, if "properly" executed. This can be boring, as Laurence suggested, but can also provide just what you're looking for, a slight change, not too dramatic. A "proper" modulation will typically be set up with a standard sort of cadence and once you're in the new key, you would typically try to thoroughly establish that key, so as to make sure it's not a brief tonicization, often times by playing an additional cadence and/or emphasizing the notes and chords in the new key that were not in the old one, sometimes emphasizing the new notes in the melody. By "proper" I basically just mean that it will be done as seamlessly and convincingly as possible. This approach generally comes from the Classical tradition and is sometimes utilized in more modern styles but more often it is not. A lot of Pop modulations are very sudden, not set up by a cadence and feel very dramatic. So in a literal sense, proper would not be an appropriate word to use, as it implies other approaches are wrong.

As to your question about modulations as they apply to the different modes of the closely related keys, there are a few things to consider. Often times when playing in a mode, we are utilizing a different sort of harmonic structure, usually not using any sort of V-I relationships, as those tend to define functional harmony and take away from the modal feeling. With this in mind, it may be good to pay attention to how you are tonicizing your different keys/modes. If you go from a functional approach to a modal one, then you'll find that your sense of tonic within the mode may not be as well or as easily established. The V-I relationship within a functional setting gives a very strong sense of tonic, especially compared to a modal cadence, so transitioning from functional to modal will likely feel much less convincing than modal to functional.

You'll also want to consider how modal and functional harmony are rather different in their actual execution. Functional harmony feels like it has a much stronger sense of what is supposed to happen where and when (not that you can't stray from it), so when you switch between the two, everything in the modal world may feel a lot less satisfying, or feel like it needs something extra to make it live up to the other section. This could become a great tool within your compositional tool belt, as it could allow you to have very strong emotional content, such as modal feeling more bland and therefore making the functional more emotional than would have been within an exclusively functional environment. You just need to be very aware of the differences between the overall feel of these two approaches and be sure to use them with clear intention, whether or not it has to do with emotion or some other intention.

In your example, you mention that you are starting in E Phrygian and suggest that E Aeolian could be a good destination. This would likely be easy to accomplish, however, it won't really feel like much has changed, as both modes are minor and are both based around E. This isn't to say that you couldn't consider it a modulation, just that it will feel much less like a modulation than a slight change in texture.

In one of your comments, you mentioned that you are more interested in algorithms of music. I'd be careful with this to some extent, depending on what you intend to do with the music in the end, as it could lead you to a very boring place, which doesn't seem to be a concern to you at the moment but may become more so later on. The problem with looking at music in terms of algorithms is that you miss so much of what makes it so interesting. Sure, you can come up with a melody and a harmony and a whole arrangement through a strictly theory based or algorithm based approach but it's probably going to sound like a nursery rhyme, ie, totally boring and predictable. Using modulations within this will take it away from that a bit but ultimately it will likely just feel like you have a nursery rhyme in two different keys kind of stuck together. If you do wish to make truly artistic music, there needs to be more than algorithms. After all, some of the best music has been in direct dissent to the theory of the time or had no real theory to describe it. I'm very driven by theory myself but it always comes back around to what sounds good. I may come up with some intricate idea that I think is really cool because of the theory, then come back and listen to it the next day only to realize that it doesn't sound all that good and I don't like it anymore. The theory driving it may be sound but the sound isn't any good and it's really all about what sounds good in the end.


I am incredibly happy to stumble upon your post, as I have been working out my own theory of modal harmony using similar principles to the ones you described in your original post.

I must object with senior basstickler who described modal harmony as being more "bland" when placed alongside tonal harmony. As long as I can remember I've been attracted to modal harmony (long before I knew anything about how it theoretically worked) and I believe it is one of the most overlooked gems in all of western music. We can see it creeping back into the airwaves with the classical impressionists, the emergence of modal jazz in the 50's and in the 60's folk revival, and I think it deserves a good look.

Here's a short summary of what I think is possible when modulating between modes.

Relative modal modulations: These work the same way moving from a relative major to a relative minor key works.

Changing tonal center without adding or subtracting accidentals: ie. C major - to D dorian - to E phrygian - F lydian - G mixolydian - A aeolian - B locrian

Moving to a relative mode required some convincing because the ear wants to hear things based around the place the music began. One trick I've been employing is getting "caught up" in a chord progression and locking into a new mode. For example, say you're in C major and the progression goes something like: C Dm G C

Next time around, say (in pop music), for the chorus, you simply hold the G and backtrack between that and the Dm. Now, you have a dorian feel (i IV). You can use other chords in the mode, but I have found that using too many can often confuse the new modal center you're trying to establish.

The 2nd option for modal modulations: Parallel modal modulations These work the same way a parallel major to a parallel minor key works.

The tonal root remains the same but the notes that follow it change, and this is done quite freely. So freely I wouldn't call it a key change but more of a color change, and because it is so fluid it surprises the ear without being as abrupt and tacky as a straightforward key change.

For example (and you suggested this early OP): E aeolian - E dorian OR G mix - G maj

Here it is most fluid to move using the circle of fifths but maintaining the root. ie. only changing one accidental of the mode. E aeolian goes most smoothly to either E dorian (raise the C to C#) or E phrygian (lower the F# to F).

But the real fun comes when you move relatively and parallelly in sequence. Ex. (In C major) C Dm G C / C Dm G / (D dorian) Dm G Am Dm / Dm G A / (D aeolian) Dm Gm Dm

I've been playing around with this idea for years now and I'm interested to hear everyone's comments. But do please play around with this before responding, as oppose to entirely looking at it theoretically. Thanks ya'll


If I understand you correctly, you are asking whether a key change of one fifth plus or minus, and a change of mode as well, would be musically tenable. I would say two things: try it out and see how it sounds. And yes, a change of key by one fifth in either direction only changes one note in the scale, so it's not too foreign sounding. Whether that's good or not depends on the effect you want.


The previous comments are all great, but I respectfully disagree that the circle is not of much use. It represents a mathematical pattern that permeates western music, 100's or 1000's of years before it was written down. Things are useful if we are willing to find a use for them. As for modes, there are 7 diatonic modes in every key, they are built from the Major scale = Ionian mode.

In order of the major scale degree they start on:

(1) Ionian (Major), (2) Dorian, (3) Phrygian, (4) Lydian, (5) Mixolydian, (6) Aeolian (Natural Minor), (7) Locrian

This is by no means the end of scales. But to the point, if you are soloing over a C maj chord or any progression in the Key of C, you can use D dorian, G mixolydian, etc.

You can change key from any starting Key to any other key. Creativity should be your guide. If it sounds cool do it, then worry about what "western" music theory says about it. Don't let theory forbid decisions. Well thought out chord progressions will make the key change sound smooth, and smooth motion from one chord (harmony) to the next is a corner stone of classical western music theory and harmonization theory. Based on your question it seems like you would benefit from working through a basic music theory text just to get the vocabulary down. As for useful chord progressions for key changes there is great book called Modulations by Max Reger, which you can get for a few bucks. I hope that helps.


The circle of fifths does show some paths to related keys, but it's also used (perhaps the main use) to show the progressive adding and subtracting of sharps and flats to key signatures as tonics change by perfect fifths.

Yes, a fifth above and below are closely related keys. A chart like the one you posted also shows the relative keys. In a major key that covers key changes to the subdominant, dominant, and submediant.

That leaves three remaining degrees of the major scale: supertonic, mediant, and leading tone.

Modulation to the supertonic is common, to the mediant is less common, and the leading tone isn't used as a key, because the diminished chord of that degree cannot be tonicized. Note that the common modulation to the supertonic is not a direct connection on the circle of fifths.

So, modulation to the subdominant, dominant, submediant (relative minor), and supertonic are common. I think that is true for many musical styles, and is certainly true for classical.

In other styles modulation to chromatic mediants are used. It sounds dramatic and can be found in Romantic era and modern music.

Modal jazz sometimes changes tonal center by half step.

Pop songs sometimes change key by half or whole step with the final repeat of a chorus. Sometimes called a "truck driver" modulation. It adds a bit of life into a chorus that risks being "played out" with too many repeats.

This is certainly not a complete list, but gives you an idea of the range of possibilities, and makes clear you aren't limited to the circle of fifths.

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