Do you mean what scale would you play over that C major progression?
If so, C major BUT you have to realize that not every progression perfectly follows diatonic major 'rules' and/or may go out of key for a beat, a few beats, a measure or more.
Take the following progression:
C / / / F / G7 / C / / / F / G7 / Am / / / Em / / / D7 / / / Gaug7 / / /
Everything is in the key of C until the D7. Play C major scale over that D7 chord and you'll hear why it won't work.
Here's an easy way to play over that D7 when you come to it;
Every dominant 7 chord acts as a V chord (or V7 in this case). You can see this in how the G7 through the progression is the V chord of the key of C.
So, that D7 can be handled as if it were the V of the key of G. Therefore, play C major scale through the progression until you get to the D7 and play G major over the D7 chord.
Next is the G7aug (or G7+5) which is voiced with the following notes:
G - B - D# - F
If this were just a G7 then we'd resolve it to the key of C, right? Yes...but that sharp 5 note takes us out of the key of C major.
But check out the C harmonic minor scale:
C - D -
Eb -
F -
G - Ab -
B - C
The highlighted notes are what make up a G7aug chord with the 5th note being a G (resolves to C) and the B note being the leading tone (seventh) back to the key of C.
So if I were playing this chord progression:
C / / / F / G7 / C / / / F / G7 / Am / / / Em / / /........D7 / / /........Gaug7 / / /
I'd play C major scale over all of this...................G major here...and C harmonic minor here.
Note: you could play G whole tone or G augmented scale over the 7aug chord but that might not lend itself well melodically and it certainly doesn't give the chord a sense of resolution since there's no C note in G augmented scale. I use augmented/whole tone scale mostly for arpeggiated runs and not so much for linear scale runs since it's all whole steps and, to me, has an incomplete feel to it.
Not wrong, just incomplete.
I don't know...is this really confusing? Does this help or no? Can any of the other wiser players clear up any confusion I may have caused?
