A genre vs genre comparison
So, a Metal Archives user has taken some research from the site and produced the below site that shows the trends in genres over the past few decades. By no means an empirical list given the limitations that MA imposes on genres and also the fact that not all albums are listed anyways. Still, thought it was interesting, and might trigger one of the more nerdy types here to do something similar.
I don't know if I might do something like this someday, but if I do, I'll make sure to include every metal genre in the book, including the ones that are absent in that list (alternative metal, symphonic metal, industrial metal, etc.).
I have been interested in this sort of genre popularity data for a while. Obviously the number of total metal releases has greatly increased over the years so I think the best indicator of genre trends would be when compared as a percentage of total metal releases, thus better reflecting what metalheads are listening to. Earlier years, such as the very early '80s would be almost 100% heavy metal which would then decline as each new genre assumes its presence and increases. This would also show if a particular genre enjoys a renaissance or resurgence within the overallcmetal community.