The film discusses the traits and originators of some of metal's many subgenres, including the New Wave of British Heavy Metal, power metal, Nu metal, glam metal, thrash metal, black metal, and death metal. Dunn uses a family-tree-type flowchart to document some of the most popular metal subgenres. The film also explores various aspects of heavy metal culture.

In Lemmy, directors Greg Olliver and Wes Orshoski explore the amazing life and career of heavy metal pioneer and cultural icon Lemmy Kilmister, the life force behind the enduring, influential band Motorhead. Over more than four decades, the drug-fueled, raspy-voiced Kilmister s career has intersected with many of the touchstone moments in rock: He saw the Beatles at the Cavern Club, he served as a roadie for Jimi Hendrix, he mentored Sid Vicious and played in both Merseybeat and psychedelic rock bands before fusing punk and metal and thus providing the inspiration for thrash metals with Motorhead. Along the way, he forever inspired the likes of Dave Grohl, Slash and Metallica, all of whom appear in LEMMY, alongside Ozzy Osbourne, Alice Copper and more.

摆开传统的束缚，1970年代是一个无拘无束的美好岁月，在摇滚乐史中既有承前启后的地位，又同时具有自己领域的独特风格。那是一个没有抄袭、不靠包装的创意时代。相对于正统主流的披头四，走红1970年代的是另类非正统音乐：齐柏林飞船合唱团、老鹰合唱团、史提夫汪达、洛史都华、戴维鲍伊，还有奇装异服却又才华洋溢的艾尔顿强，都是独霸一方的新摇滚高手。也是在这个时期，有料的摇滚乐手才能任性在录音室里创造自己的经典，无怪乎有人称赞1970年代比起现在的乐坛有趣多了。
本集和吉米佩吉与齐柏林飞船合唱团的罗伯普兰特重温摇滚乐的黄金时期，并详尽地介绍了结合了蓝调和摇滚乐精髓的疯克音乐。收录史提利丹合唱团在1970年代早期的演唱。另外还包括捕捉最真实摇滚精神的演唱会实况: 行径怪异的戴维鲍伊当年竟在摇滚舞台高处被困住将近半小时、吻合唱团舞台上的火焰险象环生……千奇百怪的突发状况在这些珍贵的片段让人看了瞠目结舌！

Little Britain算什么，Trigger Happy TV当道的时候LB还是未出世的娃娃。