Music nerd's joke. Bach (a father of 20) was bragging to Vivaldi (a priest). Bach: You know, I have 20 children. Vivaldi: Yeah, I know. Bach: I've written chorales, oratorios, concertos. I've codified the tonal system. I've invented a way of tuning harpsichords and organs so that they can play in a multitude of keys without having to be retuned between key changes. Vivaldi: Yeah, I heard. Well, Johann was going on and on about himself when, suddenly, he fell into a ditch. Bach: O help me, Antoni…