#3 CAGED guitar system

Over the past couple of days, I've been working on the CAGED guitar system. It's an intense process of visualizing scales based on the 5, common guitar chord shapes: C major, A major, G major, E major, and D major. http://coldbrains.com/CAGED/index.html is a good resource. But anyways, I'm trying to get into the nitty gritty of logical scale fingerings on the guitar...my recent discovery was that most good scale fingerings for major are not the "3 note per string" thing, but the "3 note per string" with the exception of one string having 2 notes. There are 2 good 3 note per string fingerings...but I'm not sure how they fit in yet. The goal is to have an improvisation approach that is firmly based in a chord system...it may not be CAGED, because symmetrical scales don't really follow CAGED logic...but that's the goal.

#2 Two tetrachords? I think not.

Why do we think of 7 note scales as 2 tetrachords? There are only 7 notes, so why would we think of the scale as piling 2 tetrachords (4+4=8) and include the top octave?
Let's see what happens if we think of it as 123,4567 - in other words, a trichord, then a tetrachord. Let's use the 7 modes of major (in intervallic order of "widest" to "most compressed"):

Lydian - major 1 2 3. 4567 belong to a phygian tetrachord
Major - major 1 2 3. 4567 belong to a lydian tetrachord
Mixolydian - major 1 2 3. 4567 belong to a major tetrachord
Dorian - minor 1 2 3. 4567 belong to a major tetrachord
Minor - minor 1 2 3. 4567 belong to a minor tetrachord
Phrygian - phrygian 1 2 3. 4567 belong to a minor tetrachord
Locrian - phrygian 1 2 3. 4567 belong to a phrygian tetrachord

What's interesting to note is "modes within modes," such as the lydian tetrachord in major, and the fact that Lydian and Locrian both have phrygian tetrachords, though they start on different notes.

This particular way of thinking seems to undermine the fact that major, dorian, and phrygian have dual tetrachord symmetry, which is pretty cool.

I think what this all comes down to is "tetrachordal" thinking...if you have 4 scalar notes in a row, it's some sort of tetrachord. I guess you can hack a scale into whatever bits you like, to expose particular mode pieces within a scale.

Blog #1 = progressions in major to minor

it's finally here...
A place where people who like music theory can mention their deepest, darkest, nerdiest theory revelations.
I have much to share. Let's start with an idea I had.

Take progressions in the major key...let's do "Can't Buy Me Love" by the Beatles (this may become a recurring example.)
Chorus: iii | vi | iii | vi | iii | vi | ii | V
Verse: 12 bar blues in C, with dominant 7 chords

Let's transform it into minor keeping the relative chord placements:
Chorus: bIII | bVI | bIII | bVI | bIII | bVI |ii half dim| V |
Verse: 12 bar blues in C minor, with minor 7 chords

Wow, that really doesn't work! bIII will sound like a tonic chord in a major key! I think minor keys need more emphasis on that tonic minor chord, known as i.

Comments rock.