I'm trying to understand what's going on in this small piece written for Genshin Impact game, the song's name is "Pure Sky" is about 1min long and you can listen to it here (the part I'm talking about begins at 0:27).
I believe the piece is in C major and here's what I can listen in this section:
I don't know for sure if I got that right (so correct me 👨🎓), so my question is about the last 6 measures:
I know some sort of modulation is happening, but where does that F#ø7 (or D7 without the D?) come from and why does it work?
After the diminished chord, what is going on here?
F7 -> Amaj -> D7 - Emin7The
D7 to EminI imagine it's a Deceptive Cadence where D7 is a secondary dominant, but I'm not able to comprehend the
F7 to Amajmovement.
As you can see I'm definitely not a professional musician, just a hobbyist trying to learn some funky harmonic stuff. That being said, I would appreciate (a lot) some material for studying modulation, chord substitution, chromatic movement in general, it could be books, blogs, videos, etc.