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.

Genres

Cast

Sam Dunn

Self

Chris Adler

Self

Tom Araya

Self

Randy Blythe

Self

Alice Cooper

Self

Bruce Dickinson

Self

Ronnie James Dio

Self

Malcolm Dome

Self

George Fisher

Self

Tony Iommi

Self

Joey Jordison

Self

Lemmy Kilmister

Self