Diatonic scales with CGDEbGC

Another documentation post, really.  In working with this open minor-add-9 tuning (C-G-D-Eb-G-C) I've been exploring the top three strings somewhat methodically, which is a bit amusing since the intervals of Eb-G-C are the same as the standard tuning (G-B-E, two whole steps up), and I've never really studied the standard tuning yet.  Which has led to an observation I'll get to shortly.

First was triads on these strings, done within my usual "box" of three voicings per triad, advancing each string one chord tone to achieve it.  So, in this tuning, at the nut is C/E, C/G is at the fourth and fifth frets, and C in root inversion is at the seventh and ninth frets...et cetera.  Shortly I was running through a standard exercise that has me play, up and down, backward and forward, the C major scale in triad forms, from nut to octave.  So:  C/E, C/G, C, then Dm/F, Dm/A, Dm, then Em/G, Em/B, Em, and so on.  Along with each of the main forms I also tried to note where the sus4 would go, and I'm pretty comfortable that this will shortly become a standard part of the internalized chord library.

Then, I tried adding bass notes to these basic forms, to try and figure out where the fingerings should go.  This is an interesting exercise, since there is often a choice of where a bass note can or should be located, and I'm not by any means done with it yet.  Inadvertently, the little working I've done so far has suggested a specific approach to diatonic seventh forms, wherein the chord is constructed of an appropriate bass note and an appropriate top triad.  This brings back the "tertian arithmetic" idea in a very practical way, and I'm happy to think of a Cmaj7 as an Em triad over the C3 note on my fifth string, or the C2 open sixth...or maybe the Em triad in up-neck inversions over the C4 note on the fourth string.  And that's just with root inversions;  I think I'll dig into that a little more when the library of top-three-string triads becomes more purely autonomic.

It also suggests an interesting idea with respect to tunings:  if I really can master the basic triad and sus forms on the standard tuning's intervals in the top three strings, I might be able to shift the bottom three strings around more at-will, to make available a family of tunings with a common set of top intervals.  So...with a real mastery of "GBE" chord construction, I could take advantage of fifths in the bass with CGDEbGC or CGDGBE, fourths with EADGBE or DGCEbGC (or similar), or a combination like DADFAD.

Which brings me to today.  I was able to work out the seven modes of the major scale on the top three strings, which of course is a great exercise to start to help you to "see" all the notes of the key everywhere on the neck.  I've still got a few fingering decisions to work out, or perhaps to learn them all so that they'll all be available depending on what else I'm doing at the time.  More work on up and down, backward and forward:  my fingers should tell me what is going to be most efficient.  What was encouraging was that I also started to see how I could connect a "lower octave" scale from the bottom three strings, to the "upper octave" scale on the top three strings.  The basic concept here might do well with that "family of tunings with differing bass strings" idea.

More on that as soon as I can.  With the ability to play all the triads and sevenths of a key, and the ability to play all seven modes of the scale, we're really getting somewhere important.  With that in hand, plus the ability to take advantage of the harmonic mayhem of a minor-second interval between fourth and third strings, I should become pretty dangerous in this wacky experiment.  :-)