I have a few questions about a passage in a piano piece I'm trying to analyze. I would look these questions up elsewhere but I don't even know how to word the search queries.
Measure 65 starts with a basic C major scale run. At measure 66, I believe the left hand plays an E7 chord, which resolves into an A minor in the next measure, so that's a V7-i which makes sense to me. What doesn't make sense is the right hand descending scale at 66, which moves the G to a G#. So the scale that's being played is now C-E-F-G#-A-B-C. First question, is there a name for this scale, and how did the composer know that this would fit over an E7? Is it just because the E7 has a G# too?
Also, at 68 it's an A7 chord, but the scale being played is A-B-C#-D-E-F-G-A, which is also not one of the 12 diatonic scales as far as I can tell. What are these scales?