Sure there's potential (look, this number is bigger than this one!); I just don't think you're illustrating the connection very well.
The problem isn't with my illustration, but with your obtuseness. I can't help that you're an idiot.
...the lack of a coherent aesthetic prior to the early 1990s. When we talk about 'genres' in music, we're essentially talking about groups of artists who share a basic aesthetic approach. Obviously, genres don't spring forth fully formed, so early artists tend to exhibit only some rather than all of the traits that define a genre in its mature state. This problem is exacerbated in black metal by the unusually long gap between its emergence in the early 1980s and its maturation as a coherent genre united by both ideal and aesthetic in the early 1990s.
To really understand black metal
as a genre, you need to look at the whole of its history simultaneously. If you're trying to use the criteria of 1985 to define 'black metal' (i.e. Satanic lyrical content), you're missing the boat big time. But to look at what black metal implies today (or, for that matter, what it implied in 1995) also leads to error. A more nuanced view would be to understand that 'black metal' is defined by the intersection of ideal and aesthetic, and would trace its history through the development of both. From this perspective Venom is the very first step toward black metal, and Bathory, Hellhammer and Sodom are also part of that evolutionary tree. Mercyful Fate is not, and, at the other end, neither are Cradle of Filth, Arcturus or later Dimmu Borgir. In other words, this path is how the 'conventional wisdom' was arrived at in the first place, so hashing it out again and again for ego wanking is a waste of time.
But, I suppose, the n00bs will never learn if they don't get it broken down to the nuts and bolts every couple of months or so..
Garage bands playing covers of black metal songs while writing music inspired by those songs aren't involved in black metal?
And which 'covers' would those be, since none of the bands mentioned ever recorded covers by earlier black metal bands, nor does such a cover exist on the only live recording from any of the pre-black metal Scandinavian acts (
Grim Reaping Norway - though the album does cover Slaughter's seminal
death metal anthem, "Nocturnal Hell")? All of the bands in question were squarely death metal. They sound like death metal. Their songs deal with the same ideas as death metal. Their technique is drawn from death metal, and the bands they were influenced by were...death metal. I hate to break it to you, but the internet exists at this point, so it's not at all difficult to hear these recordings. The days when you could make bullshit claims about old demos with impunity have long since passed.
I think you're going to have to spell it out judging by other responses, what are the big changes made by Mayhem?
Ultimately, Mayhem was probably the least inventive of the Norse bands (or at least the band that remained most grounded in previous generations of metal). Their biggest impact was at the level of ideal: they kicked off the ideological arms race that pushed black metal towards ever greater expressions of conceptual (and aesthetic) extremism and sonic inaccessibility to normals, leading on the one hand to Graveland and the other to Ildjarn. Musically, while they weren't particularly innovative at the level of basic technique, they were instrumental, I think, in creating the idea that black metal could be made both extreme and inaccessible through production technique, but retain a kind of dark beauty through more attention to the articulation of melody and abstraction in structure.