Back when I was in drama camp, we had a piano player who was very impish. I think her name was Alexandra. She was probably all of 16 and a gifted musician who played the piano with the kind of ease that would make Victor Borge proud. And like that musician, Alexandra had a witty sense of humor. She was often at odds with our director, and very often, when she was mad at her, would play some musical number one octave or key above or below the normal range specified. Or would hit a wrong note at the precise moment when it would do the most damage and yet be the most subtle.
I once had to do the flagship song from "A Chorus Line" with the piano playing at such a high octave, it was like dancing to a music box.
Alexandra would have appreciated this video. My musical friends will understand this, but for those of you who don't know what a subtle thing like playing in a different key can do, it can turn Christmas carols into horror film soundtracks.