I used to sing “The Ballad of Mack the Knife” (and not the more sanitized translation that hit it big on the radio in the 50s) to my niece when she was a baby, because it’s one of two songs to which I actually know all the lyrics. I am extremely grateful that her mom just gratefully accepted someone else was calming the baby and never made a moment’s fuss that I was singing about rape and murder (and I did stop before she started talking, heh; now she’s stuck with The Circle Game if she wants singing to).