In the very first scene shown where Ronald is giving Cecile cello lessons (after the scene when Sebastian and Annette first meet), it shows the outside of a building first. You can quite clearly hear Ronald say "let's try the G major scale" . Then it focuses in on them and she's playing the G major scale. Ronald then says "try again, and remember, the third note is sharp."

The only problem? The third note isn't sharp in the G major scale.

For a guy who's writing an opera and attending Juliard, I think he should have known better.