-Hell never existed. The original hebrew word for hell was 'gehenna'. Google it; it's a physical place. The other word often translated as hell is 'sheol'. You can google that too, it's just a concept of nothingness from which we're born and return to when we die. No judgment of any kind was attached to sheol.
-Satan never existed. The original hebrew word satan simply meant adversary. It's used twice in the bible, once during job to refer to the angel sent by God; the other time I forgot. The other word most translated as Satan is Lucifer, which itself was a translation from 'the light bearer' - a term referring to the planet venus. Lucifer literally is Venus.
-The original hebrew word for sin most associate with eternal condemnation, but hell didn't exist in the original literature as we've established; sin only denotes crime and consequences in life and is most closely translated to 'mistake'. Therefor if you can think of any consequences of playing heavy metal music, to this extent it could be called a mistake or a sin.
-The entire bible is a lie, more could be said about this but I think the above is sufficient for now.
-God created you which created heavy metal music, so God approves.