Nononono lemme explain
Remember that scene where both sherlock and eurus play the violin
Yeah at the begininng sherlock starts to play Bach's Sonata No. 1 in G minor but eurus stops him bc she recognized the piece just by hearing one chord
And about moriarty, it was from the reichenbach fall when he and sherlock had tea and shit. So when he entered the door sherlock was playing a bach piece i think (forgot the name)
And he replies with "Johann Sebastian would be apalled."
I love them for mentioning him