Learning the cycle of 4ths / 5ths

viz

Hey. The outer green and blue circles are all major in all 3 pictures, as ionian, lydian and mixolydian are all major modes.

The minor chords are the inner green and blue circles, as aeolian, dorian and phrygian are all minor modes.

Thus, in the first picture, the common one, with ionian and aeolian, you can see that C ionian has no sharps or flats, and neither does A aeolian, so A minor is related to C major.

In my Lydian/dorian picture, you can see for example that C lydian has 1 sharp (the sharpened 4th from the major scale), as does A dorian (the sharpened 6th from the natural minor scale), thus also proving that A minor is related to C major.

And in my Mixo/Phrygian picture, the C Mixolydian has one flat (the flattened 7th from the major scale) and so does A Phrygian (the flattened 2nd from the natural minor) - so again the A minor is consistently related to C major.

So whichever picture you use, you can see the relative major/minor pairs.

fnpt

Brilliant, thanks. Have a wisdom.

UnclePsychosis

I come from a classical background and its really fascinating for me to see how complicated some people (guitarists!) make this stuff. Or, I suppose, a more accurate thing to say is that if you haven't put in all of the groundwork learning all the baby steps then learning stuff like this is hard! 

When you learn a classical instrument like the flute part of the natural learning process is to learn all the note names, and, gradually, you learn all of the major scales (and minor too) and probably all the arpeggios too. You internalise precisely which notes belong in which keys, because you don't ever play stuff based on finger shapes or patterns---all learning is done, from day 1, by using proper note names. Once you have all that down, then things like fourths and fifths become easy.

Modes are an interesting one. When I learnt about modes as a young jazzer, they were dead easy because I knew my major scales inside out and back to front, and if you know your major scales then there is a cheat to learning modes. 

For example, Dorian modes are a major scale, but starting on the second degree of the scale. So to construct a Dorian mode, you go down a tone, take all the notes from the corresponding major key, but play them starting from where you started. E.g for D Dorian, you go down a tone (to C), take all the notes from C major, but play them starting from the D----so D Dorian is D E F G A B C D. You can then delve into chord theory, by "playing a note and missing one" to make chords so D - miss one - F - miss one - A - miss one - C - miss one gets you D-F-A-C, which is, of course, a Dm7 chord. So Dorian is a minor mode and it sounds great over m7 chords (which is why they get used in jazz so much).  

Similarly, you can construct a mixolydian mode by again taking a major scale but this time starting from the 5th instead of the 2nd (as in Dorian). So for G mixolydian you go down five, take the notes of that major scale, and play them starting at G. Down five from G takes you to C again so play G A B C D E F G and you have G mixolydian. Using the "play one, miss one" way of constructing chords from scales gets you G-B-D-F which is of course a G7 chord. So mixolydian modes are major and sound great over 7 chords (which is why they get used in jazz so much).  

All of the modes correspond to a major scale, but starting from a different point in the scale. If you know your major scales you already know all the modes! 

Basically, what I'm trying to say is that learning your major (and minor, although major is more critical) keys and scales inside out and back to front is a really, really helpful exercise. They help you understand so many aspects of music. So, if you want to learn music theory but haven't learned your major scales (and I mean LEARNED them) then you're probably hindering yourself.