A lot of people say that Steppenwolfs"born to be wild"was the first heavy metal song....i disagree ..i reckon it was Jonnie Kidd and the pirates song "shaking all over"....i might be wrong....anyone?
Yeah,you could be right ,Mark rae,I was looking at the Vince Taylor version of the song..."heavy metal thunder"does appear in the Steppenwolf song....though these were just lyrics which John Kay had heard from visiting British bands...
Inna Gadda Da Vida by Iron Butterfly is considered to be the first heavy metal song, Born To Be Wild is a pure rock song IMHO. I prefer Magic Carpet Ride myself.
Surely anything produced before the early seventies was considered as progressive rock; ie Emerson Lake & palmer or cream. The likes of Led zeppelin etc then started the gendre of heavier rock.