Pete Townshend and Jimi Hendrix are the pioneers of harder playing. Pete Townshen though wasn't a real class of a player was the first to do Stage Antics, Experimenting with Feedbacks and he was the first one in several of the tricks. Jimi Hendrix took this thing to a different level plus his own innovations. Infact Hendrix is given the credit for Feedbacks, Stage Antics, etc.. where Pete Townshend was the first to do it. Noticing the popularity of Hendrix with this Hard Blues, countless other came into the bandwagon trying out the forumla. People like Jimmy Page, Ritchie Blackmore, Uriah Heep, Wishbone Ash, Black Sabbath, etc.. followed the footsteps of Jimi Hendrix is creating harder music. Each of these were innovators and deserve great respect in their own right. Each of these kinda branched into a different style that is aped till today.
Jimmy Page - Hard Blues Rock
Ritchie Blackmore - Hard Rock with Neo Classical Influences.
Uriah Heep - Progressive
Wishbone Ash - Twin Lead Guitar Harmonies. Now you know where Maiden copied.
Black Sabbath - Heavy Metal, Black Metal, Doom Metal, Gothic, etc...
All of them though heavily influenced by Hendrix, have gone ahead to innovate further, than just practising faster licks because the brain cannot think further.
I'm the one that has to die when it's time for me to die, so let me live my life, the way I want to. - Hendrix
If you can remember the '60s, then you weren't there. - Unknown
I'm shopping around for something to do that no one will like. - Jerry Garcia
Don't compromise yourself. You are all you've got. - Janis Joplin
On stage I make love to twenty five thousand people; and then I go home alone. - Janis Joplin