Not sure if anyone else have come across this but I have encountered a bug where music would be playing from places they're not supposed to play from. I just recently experienced a Rune node playing lute music and when I harvested the rune, the music was gone. I don't think runes are supposed to or even know how to play the lute, otherwise it must have been a very special rune. I've also heard singing coming from out of nowhere and there were no NPC for miles that could sing, unless Tamriel is being haunted by a ghostly bard which is highly unlikely.