Intro → quite chordal harmony, lots of clash and resolution used.
Section A → sound percussion (like recitative notes, use inspo from lessons), but then layer different melodies on top with intertwining harmonies
Section B → some dissonance and some diminished harmonies to heighten suspense? could use tonic noise as a pedal with staccato on lower voices and then doubled by sopranos up two octaves.
Section A' → harmonies are smoother again, could use ambiguous harmony at some point by evading thirds and doing some perfect fifths in different vocal lines, could also use circle of fifths chord progression.
Coda - sweet harmonies used, I would like quite unexpected chords that sound nice and lamenting before having a happy finish at the end.