It would be "Black Metal" only by association. I'm relatively certain that a large proportion of the Classical music I listen to would, when arranged for a Metal band, be Black Metal (generally of the In the Nightside Eclipse variety).
Most of the classical I've heard that has been transcribed for the electric guitar -- whether Bach, Beethoven, Chopin, or Brahms -- almost always sounds like Yngwie Malmsteen or Dragonforce. As classical generally tends to utilize a much broader range of notes than metal, it inevitably suffers from losing its emotional impact when played on an electric guitar -- which, due to its tone quality, seems to suck the emotion out of the notes being played, regardless of genre. Exceptions in metal in particular tend to involve heavy amounts of distortion, tremolo picking, or a focus on the lower end of the instrument.
I'm wondering if this has to do with the inherent incompatibility of an electric instrument with classical music, or if most of the people who play classical in a "metal" style are just being obnoxious on purpose. I don't play guitar, so I don't know, but if there actually are
metal versions of classical pieces where the guitar is used in a way that doesn't make the piece sound like a bombastic Yngwie Malmsteen finger exercise, it would be good to let the world know about it. Until then, it looks like every search on YouTube yields stuff like this:http://www.youtube.com/watch?v=pn0JxTiiGDEhttp://www.youtube.com/watch?v=Ypx1gCNVIZA&feature=relatedhttp://www.youtube.com/watch?v=bASrMSLp9Bs
Is there anything that can be done to a classical piece (Brahms, Bruckner, Liszt, etc.) on a guitar that would ever make it sound more like this?http://www.youtube.com/watch?v=osD0RdTMTMA&feature=related
...or is it better that each set of musical statements sticks to the instruments which work best for them?