Over a year ago I saw this documentary at the Melbourne International Film Festival (I think). Not being a headbanger, per se (though I do like some heavy metal), I found this documentary very informative and interesting.
It's presented by avowed "headbanger" (so called for how fans react to this music) Sam Dunn. Now, there is no doubt some interest in a fan-boy waxing lyrical about their favourite things, but what raises this documentary above the average is that Sam Dunn just happens to be a scholar-an anthropologist-thus ensuring that the content is well thought out and articulated.
Of particular fascination to me was the "family tree" diagram featured frequently in this docu of how the various genres of heavy metal relate to each other...that must be the anthropology angle kicking in, I think. When I contacted a site related to this docu, someone mentioned that the DVD of this may have the diagram (or at least future editions would) as a distinct element of the DVD.
The docu covers heavy metal as a genre-it's various sub-branches and its putative father, so to speak. What was particularly good about this was that whilst Dunn did posit who he thought created heavy metal as a genre (Black Sabbath), he does provide video footage of bands which piqued my interest in the subject and which could perhaps be argued to have created the genre themselves. In other words, you don't get a completely biased view of the subject from Dunn.
Many of the legends of the genre are interviewed in this docu-Tommy Iommi from Black Sabbath, Alice Cooper, Lemmy from Motorhead and Iron Maiden's Bruce Dickinson. Not being a great fan of Iron Maiden, I must say that Dickinson was a highlight of this docu for his honest and insightful comments on the art of performing.
As there is a school of thought, perhaps, that Metallica are the pinnacle of this genre, they are conspicuous by their large absence from this docu.
I've reviewed some heavy metal albums at Amazon under this id. e.g. Coldseed.