The origins of metal are interesting indeed. Basically, The Gods made heavy metal and they saw that it was good. they said to play it louder than hell, we promised that we would. When losers say it's over with you know that it's a lie. The Gods made heavy metal and it's never gonna die.
This ^
but to go into further detail, the classical composers hit on it, white jazz and swing players hit on it, boogie started long before rock, white country artists hit on it, ancient Celtic folk hit on it, that came here and became bluegrass became country. There is one school of history that claims blues was influenced by Appalachain folk which came from Brit blood... then combined with slave field chants... so its all very complicated and comes back to those "Gods"
Still it was the likes of Hendrix, Clapton, Beck and Page that took those blues ideas, reached further with them and applied distorted guitars, along with their bombastic druming buddies that started the thunder
prime example in my book... Zep took this
and did this... wait for it, imagine never hearing such a thing prior to 69 and this a-typical blues number starts playing... then all of a sudden, its there in your face.... just a pumpin'
[ame]http://www.youtube.com/watch?v=wz4gRjI-HRA&feature=related[/ame]
excluding Jimi, The Yardbirds and what ever Cream and The Who did with heavyness we never had any such in your face riffage prior to Zep that I know of.
Still though here is Beck and the Yardbirds in '66 with a classic gallop type riffage
which came from this
now I like black music but make no mistake they were a different kind of "heavy" and definantly not one ounce of "metal"... till Jimi but there was still a vast difference between Jimi's and Jimmy's take on distorted guitar riffage.