Book excerpt: The definition of 'heavy metal' is often a contentious issue and in this lively and accessible text Andrew Cope presents a refreshing re-evaluation of the rules that define heavy metal as a musical genre. Cope begins with an interrogation of why, during the late 1960s and early 1970s, Birmingham provided the ideal location for the evolution and early development of heavy metal and hard rock. The author considers how the influence of the London and Liverpool music scenes merged with the unique cultural climate, industry and often desolated sites of post-war Birmingham to contribute significantly to the development of two unique forms of music: heavy metal and hard rock. The author explores these two forms through an extensive examination of key tracks from the first six albums of both Black Sabbath and Led Zeppelin, in which musical, visual and lyrical aspects of each band are carefully compared and contrasted in order to highlight the distinctive innovations of those early recordings. In conclusion, a number of case studies are presented that illustrate how the unique synthesis of elements established by Black Sabbath have been perpetuated and developed through the work of such bands as Iron Maiden, Metallica, Pantera, Machine Head, Nightwish, Arch Enemy and Cradle of Filth. As a consequence, the importance of heavy metal as a genre of music was firmly established, and its longevity assured.