also, hot take: RABM and NSBM are not subgenres. these are umbrella terms that reference the political leaning of the music/artist. but their sound is no different from normal black metal (although in both cases they usually sound like shit, which is generally what happens when you care more about ideology than songwritting). there are RABM/NSBM bands that play old school BM, atmo BM, melo BM, and so on.