It is pretty given that Led Zep and Black Sabbath were the originators of the heavy metal movement. Given that I just wrote an eight page paper on one of Led Zep's songs, I think I'm fairly saturated with that kind of material. Besides, I need to look at more modern movements, as in the past ten years, for my lecture, since my professor is covering most of the other movements (including grunge! dammit) herself.