Welcome, Andrew.
the psychological association that exists between the spiritual concept of goodness and saintliness and the notational accident of the absence of sharps and flats in the key signature
Good heavens--it never occurred to me that there might be such an association. I've played a lot of music, and none of it ever looked spiritually good or otherwise to me. Sound, now--sound can certainly evoke images. Night on the Bald Mountain, for ex.

I'll PM eta about this.