Believe it or not, one of the defining moments in my relationship with black metal came the first time I heard Nargaroth's Jahreszeiten, and specifically the repetitive riffing on the last track, "Winter". This was my introduction to this band, before I knew of their earlier, more notorious records, as well as before many of the genre's foundational names. This kind of monotonous melodic austerity captured what I found to be essential in black metal, and shaped how I continue to appreciate it today.
