Tracing the origins of black metal is less like searching for a needle in a haystack and more like wondering through a graveyard at midnight, glancing about at this ghost and that and trying to decide which ones are corporeal enough to still qualify as human.
This is not a problem unique to this particular genre – entire books have been written on which was the first rock & roll single, with few of them offering any firm resolution – but, in the fervid tenor of extreme metal, the question has taken on an almost monumental (certainly earnest) importance that it tends to elide over the very notion of influence in the first place.
I'm already covering the subject of elusive lineage in another article for this year's BMHM, so I don't want to belabor that point; suffice to say that, with few exceptions, most of the bands covered here are of dubious distinction as full-time black-metallers. In an era where no such thing actually existed, you'll forgive many of these entries for only occasionally exhibiting the traits which would ossify into prerequisite tropes by the genre's second wave. Some acts, such as Mercyful Fate, are often cited as hugely influential to the development of black metal, although little of their actual music outside of the pageantry and hellish thematic occupations are present in modern black metal at all.
That's quite all right. We will take this motherfucker apart anyway… after all, Norwegian black metal came together piece by piece over a period of years – which we can loosely define as 1980 to 1987 without splitting too many hairs – so it behooves us as celebrants of the genre to itemize its innovations, milestones and flagrant anti-charms.