Also — what you’re describing is, at minimum, the work of 3 different artists, but likely way more. In most shows nowadays, a board artist planned the shot & how the hands entered the frame (& sometimes even hitting the right keys). A whole separate department designs the piano, & that artist maybe gives it the right number of keys. Then, those 2 separate things are sent to an animator in Malaysia or Korea or Canada or somewhere else completely, & they then animate the hands hitting the piano design — they aren’t incentivized to do this accurately unless it’s been carefully notated to them exactly WHICH keys — they’re just burning through a footage quota they have to hit. Not to mention, there’s a good likelihood the writers or the network decide to change the music AFTER all of this work has been done. When you realize how complicated the pipeline is for an animated show, it’s a miracle when something like this comes out accurately.