Recently I learned certain songs like "Ring around the Rosie" and "Are you sleeping Brother John" are about sicknesses and the Great Plague. :C
Example: "Ring Around the Rosie"
'Ring around the rosy, ( The Great plague of London in 1665 had symptoms of rosy red rings around the skin.)
Pocket full of posies (A belief in 1665 during the plague was that sweet smells may keep the plague from carrying, and posies were sweet smelling flowers.)
Ashes, Ashes ( To keep the plague from spreading terribly, dead bodies of plague victims were cremated.)
We all fall down.' (I'm just guessing, but I think that means we all DIE.)
There is also "Are you Sleeping?" The song was created during another sickness, (not sure which) and it depicts a young girl trying to wake her brother. The line "Mourning Bells are ringing!" also depicts mourning bells which were rung to mourn the death of someone (I think). When you think about the song it's all very sad :c.
There's many other grim and sad songs, and if you could post them with explanations to the lyrics, that would be nice. Feel free to correct me, because I'm not quite sure of the idea myself!