Nothing wrong with the music itself, its the lyrics that sung with the music. Music is music, but if you add demonic, sad, evil, devilish lyrics to the music, then thats when it becomes bad, and wrong, through Christian eyes. and that demonic grunting voice in rock music? what all that about? Can you understand it? When i listen to rock music, i just listen to the music itself, without the lyrics,
So nothing wrong with rock music itself.