Bogwitch

…She hardly knew how to explain to a person considerably more musical than herself the effect it had on her to hear a piece played imperfectly. It made audible the difficulty in the music; it made audible the demands made on the performer. It was moving in a fashion that a perfect performance never quite seemed to be.

— from The Attenbury Emeralds
by Jill Paton Walsh (after Dorothy L. Sayers)