Chapter 10, Page 5 The lyrics are...

Of course, it would probably help if Mary actually knew the worlds besides some bits around the refrain.

Well, then there are the songs she does know all the words to that involved drunkenness, murder, philandering... And these are songs her parents listen to!

And she's still pretty oblivious. Probably helps that the oldies tended to be a bit more subtle than some more current songs.