They have a handful of Celtic-inspired songs, and tons of blues and blues-rock based ones. If you listen to them only expecting to hear the origins of metal, yo

They have a handful of Celtic-inspired songs, and tons of blues and blues-rock based ones. If you listen to them only expecting to hear the origins of metal, you're going to be disappointed. If you have an understanding of how heavy music was at the time, then you'll understand why they were considered so heavy.