I listen to all kinds of music. I also play it. most of the stuff we play is christian, we have even written some christan songs, but not all of it is.
I listen to led zeppelin, pink floyd and many others. I read steven king (or did for many years) all my friends also do this.
It did not make me a crazy, horrible sinner, Nor did it change my mind about God or keep me from doing Gods things. There is nothing wrong with it scriptural. and as grandpa so rightly said, if we are to go into the world, we are going to have to listen to this stuff.
however, if it does affect us, or we can't separate fantasy from reality and struggle. i would say it would be dangerous to do these things,