Intense Theory Question...

[BluesGuyJ]

So I was working on my triads, just becoming more familiar with them.  I was playing C and E minor in as many ways as possible up and down the neck. 

I don't know the name of the inversions, but I played a C in a "513" inversion, barring the sixth fret, the D, G and B strings. I then played an E minor,
a "351", rooted on the D, G and B strings as well.  I noticed that the only difference in freting, was that when I played the E minor, I fell back one
fret on the G stringm but held the same notes on the D and B strings. CEG to EGB, going a half step from C to B. I then noticed that E minor (or EGB) make
up the, what I shall call flavor notes, of a C major chord.  I analyzed all of the chords in the key of C and came to the following conclusion. 

I = root, third and fith of III

II = root third and fith of IV

III = root, third and fith of V

IV = root, third and fith of VI

V = root, third and fith of VII

VI = root, third and fith of I

VII = root, third and fith of II. 

This is all possible of course when looking at each chord along with its 7th interval in the chord.  C(EGB E minor), D(FAC F major), so on and so forth. 
When you start at any note of a scale in a normal 7 note scale, if you build a chord 2 steps away from that chosen note (following the wwhwwwh pattern),
you technically derrive the "flavor notes" of that chord in its 7th form.  I think you will get the jist of this and I know you probably know all of this,
but does this concept have a name?  I'm pretty proud of myself for figuring this out! 

Hope it makes sense as well lol.

 

[Osensei]

Re: Intense Theory Question...

Chord substitutions are what you have discovered! :banana: Although, you have only scratched the surface. As you can see, there are many chords that are subsets and supersets of one another!

Isn't it amazing how math in general and set theory more specifically reveals itself once we reach the threshold of understanding?:lmao:

E min (EGB) is a subset of C maj (CEG)! In set theory the two chords or "sets" intersect at point E & G. Combined into a single chord they would produce a C Maj 7 chord. But let's try some others:

GBDF = G7, but wait...! GBD = Gmaj and BDF = B dim, so dom 7th chords also had a dim component to them, right? Could that also mean that the modes or scales that I would use to improvise on a G7 might also work on a B dim? I'm certain that this has the light bulb going off in your head right now, but unfortunately we have not ventured very far from the diatonic universe.

Popular music in order to be hip, in my vocabulary, has to be bluesy, jazzy or both! So far what you have realized will not take you far from the standard diatonic modal considerations. In other words if we are talking Cmaj and you play E G B then it will just sound like someone playing in they key of C Maj! We must learn to extend our tonal choices and create more interesting tonalities than just what can be derived from diatonic choices!

Consider this rule! "Any two chords having two or more notes in common are qualified to be substitutions of one another!". This rule expands our universe beyond mere diatonics! Consider the two chords G7 and Db7! Am I saying that Db7 can be substituted for G7? Absolutely!

G7: GBDF and Db7: DbFAb(B) have the notes F and B in common! This type of substition is quite common in Jazz and is known as a "tritone substitution" of the V7 chord!

Thus the chord progression: Dm7 - G7 - Cmaj7 is transformed into Dm7 - Db7 - Cmaj7.

Here is another! Take the chord C Maj7! Now let's consider a substitution of E7(+9). Like this:

Cmaj7: CEGB and E7(+9): EG#BDG

C Maj7 and E7(+9) have 3 notes in common. Actually, you could claim they have 4 in common because the D in the E7(+9) chord is the 9th of the Cmaj7 chord as in C Maj 9!