Bow your head with great respect and genuflect, genuflect, genuflect is a line from the Tom Lehrer song The Vatican Rag. The song was released after Vatican II and pokes fun at the Church for updating Mass and making it more accessible to the people.

On a personal note, my Catholic Grandmother hates this song. She hates that I know all the words to it, and that I have, on occasion, tried to sing it to her when she suggests that I go to church with her.