bands who came before, and influenced, the first wave of heavy metal, but were themselves, NOT metal.
Proto metal is stuff like Blue Cheer, Dust, Jacula. Black Sabbath on the other hand is 100% heavy metal, not proto metal at all.
Well, proto-metal isn't technically a genre, but proto-metal bands are basically the bands that started to bring together the elements of blues, rock, etc. that influenced the beginning of the metal genre. Bands like Zeppelin and Deep Purple are very good examples and Black Sabbath is the best example as they are, for the most part, widely considered the first truly metal band.
