metal represent a headbanger journey be an entertaining documentary about sam dunn and a heavy metal fan try to find an answer to the question why metal fan be always outcast by the general public and why metal itself be often not recognize a a valid form of music . in do so dunn categorizes metal into different subgenres ( a process that will always lead to a lot of discussion among fan a prove by the imdb board ) and he try to find the origin of metal and divide his survey rather cleverly in chapter like religion and satanism and gender and sexuality or death and violence . the result be not really ground breaking . if you ever be into metal and you will already know most of the fact present here . what make the movie worth watch anyway be the comment by some genre defining and some underground musician that have be interview . unfortunately and sam dunn couldn not get all the important metal band and so he have to do without contribution by deep purple and lead zeppelin and juda priest and metallica and anthrax and megadeth or pantera and which make metal seem a bit random . very rarely be we get substantial insight into the mind of those who listen to metal or even contribute half their life to it . an explanation like metal be always there for you come what may just isn not very enlighten . i mean soccer fan will say the same about soccer and right . so and no and this documentary doesn not tell you thing you hadn not already know before and but it help you to relume your passion about metal . and the interview be often quite hilarious . just watch out for gaahl and a wine fill glass of cognac and the mention of satan . you will understand what i mean when you see it .