Oddly enough, for being one of the truly iconic albums of the entire second wave of black metal, De Mysteriis is one of the few that really avoided being directly copied. Almost everybody from 1988-onward in black metal was heavily influenced by Mayhem, that much is true. It's more importantly, how the songs come together, the kind of austere mood it channels throughout it, etc. that most bands have never even really tried to do, or if they did, they ended up stumbling onto something completely different from what Mayhem did here.
Most importantly though, it's great because it's brilliantly crafted and imaginative. The songs are simply fantastic throughout and have some of the best riffs in black metal, period*. One of the things that makes them great is how Mayhem knew how to build up tension and atmosphere throughout by using subtle variations on a riff here or Varg's bass line there - little things such as that goes a long way toward making this a great record. They're riff-heavy and genuinely flow incredibly well together. Hellhammer's best drum performance is on this record, bar none - while he plays at a frantic speed much of the time, he knew how to keep things rhythmically interesting among the hyper-speed thrash and blast beats with, again, little subtle variations in rhythm. And there's Attila's vocals, which is sort of a King Diamond situation - you either like them, or you don't. Not much middle ground. Myself, I love them and his unorthodox, strange performance is a huge highlight of this record.
It's a fantastic record. Alongside Under a Funeral Moon and the Emperor/Hordane's Land split, it ranks as among the peaks of black metal's second wave. Takes some time to really sink in and absorb, but it's worth the time to get familiar with.
*another note about the riffs is how heavily they're influenced by earlier heavy metal - the thrashier riffs in particular really bear a resemblance to Venom at times, and the two leads on the album have a sort of Mercyful Fate feel to them as well. It's interesting to note as a contrast to much of the rest of the Norwegian scene, which took influence from Bathory and Venom of course, and then tried their hardest to divorce themselves from earlier metal, to varying degrees. They're really, really fucking great riffs; I can't count the number of times i've had the intro ones to "Cursed In Eternity" or the title track stuck in my head, among numerous others.
