Desc: Metal Mania: Directed by Christoph Dreher, Rolf S. Wolkenstein. With Erosion, Lemmy, Metallica, Motörhead. While debate rages on about Heavy Metal and its merits as a musical genre, most commentators agree that Heavy Metal kicked off in the 1960s with the blues-based rock of bands such as Led Zeppelin, Black Sabbath and Deep Purple.