Going to try this one more time. It is in a sense a maj triad with a #6 extension. (It evolved to this idea much later, and quite frankly is never used.) Actually, in it's simplest form, a 1st inversion minor in which the upper 4th is raised 1/2 step (or the original root raised). It is not "the augmented chord with a 6 extension." This idea has nothing to do with the augmented chord. Augmented chords (#5) are completely different puppies from Aug 6 chords. Augmented 7th chords are completely different puppies from Aug 6 chords.

The easiest explanation is this: In it's first machinations, the sub dominant minor triad (iv) is turned into a dominant chord by raising the first inversion 4th by one half step. (aug 6)(sorta where the tritone sub really gets it's start) In actuality we have a dominant IV7 to I or i, (a classical slight of hand) instead of the normal V7 to I or i, or in time where needed. This IV7 was annotated to a It6 or Fr6 or Gr6 (numbers in upper case,) or Aug6/X to I or i. The early evolution of secondary dominants. More evolution or machinations later to nowadays, they're known as secondary dominants. Or just plain dominants. The real difference between dominants and Aug6 is the resolution of the tritone. As I said long ago. The real important item of this chord is Aug 6 =3rd moves down, 7th moves up.
Dom 7 = 3rd moves up, 7th moves down. This idea becomes very important in terms of modern harmony much later.
More specific and general info is at:
http://www.utexas.edu/courses/mus612b/fmain/fdocs/notes/augsixth.html

I hope this clears this matter and puts a stop to this silliness.


[Edited by griphon2 on 02-15-2003 at 02:01 AM]