Help analyzing a few bars in a piano piece

Question

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?

Answer 1

The RH in m.66 and 68 are not scales (and are not being played in scale format.) Usually in analysis we would not label something that is not played linearly as a scale.

M.68 is easy - it is an A7 chord. In a couple of places there is a short run (A G F# E) that include some passing tones between chord tones.

M.66 includes figures that decorate the chord tones of the E7 chord. Each set of 4 notes includes at least two notes of the chord. The four-note figures do not follow a specific pattern. Many look like a "changing note" type figure, although they technically aren't.

Answer 2

bar 66 is the chromatic minor scale : G#,F,E,D,C,B,A,G#,F,E,D,C,B,A -> just mind the odd notes 1,3,5,7,9 etc. (at the beginning in 3rds then with the upper changing note.)

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...

bar 68 is the V7/iv (secondary dominant of D-minor). Dm is the subdominant of Am and is reached by making Am -> A7 (V7 of Dm)