Headbangers, unite! It's a "Metal Evolution," courtesy of the same production team that made the 2005 documentary "Metal: A Headbanger's Journey." One of those producers, Canadian anthropologist and filmmaker Sam Dunn, also is involved here as host of the 11-episode docu-series, which follows Dunn as he explores 40-plus years of heavy metal history by visiting bars, back alleys... imdb.com