I tried easing my brother into metal once because he occasionally will listen to some metalcore and deathcore. I suggested some At The Gates and Dark Tranquillity to his response, "What the fuck is wrong with you? I believe in God." I don't foresee myself ever trying again, as he completely misses the point of metal no matter how I try to explain it.
Mussorgsky's Night on Bare Mountain would be a better example.
It's already a step up from Immortal's videosYeah, I'd say that piece is far more black metallish than "O Fortuna".