Family-Unfriendly Death/Ballads

In the Scottish ballad "The Twa Sisters", two constantly bickering princesses who have fallen in love with the same man go for a walk on the banks of a swollen river. One comes back and says the other one fell in and drowned. No one can find the body - but a few months later a wandering bard shows up with a harp made from the dead princess's bones and strung with her hair. The harp plays itself and sings that her sister pushed her into the river. In Patricia C Wrede's retelling of the story, there is a third princess, who knows her sister was a liar and suspects the harp might, too -- especially since there are lies in what it said.
- Loreena Mckennitt performs an excellent version of this ballad called The Bonny Swans (which is easily findable on YouTube).
- In yet another version (one with a particularly upbeat and sunny tempo), the elder sister's punishment for drowning her sibling is being boiled in lead. So much fun to sing with one's actual sisters!
Ballads in general are full of this sort of thing. Perhaps the most horrifying of the lot is "Long Lankin" (Child #93), in which an itinerant serial killer murders a lord's baby (spectacularly averting Infant Immortality in the process) and then his wife:

"We will pinch him, we will prick him,

we will stab him with a pin,

And the nurse shall hold the basin

for the blood all to run in."

So they pinched him and they pricked him,

then they stabbed him with a pin,

And the false nurse held the basin

for the blood all to run in.

- Followed by Long Lankin being hanged and the nurse being burned on a pyre at the end of the song.