Metal: A Headbanger's Journey (2005)

A documentary about Heavy Metal music and the legion of fans that embrace it. The genre is a huge money-spinner, but its notoriety and associations with aggression keep it on the fringes of acceptability; I would argue that’s where it needs to be in order to survive.
The filmmaker is an anthropologist. He brings that discipline's methodology to his work, meaning it’s not just a fan’s perspective, it’s a study of a cultural group and their system of beliefs.
Perhaps most importantly it does what many modern documentaries neglect to do: it asks a pertinent question and through investigation and elimination it offers an answer to that question.

4 overblown moral panics out of 5