On the topic of not-rocks, when I was growing up, I had a cassette tape that had a bunch of folk tales on it. One of them (if I remember correctly, which I very well may not) had to do with a king who was sick, and sent his three sons out looking for a magical cure. Two of the sons get bored of the quest and quit; the third actually found the cure and was bringing it back when his brothers found him, killed him, buried him, and took the cure home to claim the reward. But reeds grew where the good son had been buried, and someone cut the reeds and made a pan flute, and when the pan flute was played, it sang about the brother's death in his voice.
I mostly remember it because the song was creepy and got stuck in my head a lot. I have never been able to successfully Google the story or its audio. I really wish I could find it again, though, because nostalgia.