Some people say Heavy Metal was born when:1- a riff first drove a song.. that would be You really Got me by The Kinks.
2 - Big drum rolls were recorded ... Then should be Keith Moon in I Can See for Miles.
3 - Distorted melodic guitar lines .. Then The Beatles with Helter Skelter.
4 - Lyrics related with Evil nature.. then The Rolling Stones did it with Sympathy for the Devil.
5 - Long and complex guitar solos .. Then that would be Jimi Hendrix with Voodoo Child.
6 - heavy guitar sound and high pitched vocals... then it must be Led Zeppelin I.
7 - Violent attitude... Then The Stooges with I Wanna Be Your Dog.
8 - Heavy Metal on the lyrics.. SteppenWolf with Born To Be Wild.
9 - Heavy in the record title - Iron Butterfly with Heavy.
10- All together ... then it happened when Ozzy met Tommy Iommy who met Geezer Butler who met Bill Ward..
