58Peter Green

Graham Wiltshire/Hulton Archive/Getty ImagesIn late 1966, Peter Green had the job of replacingEric Claptonin John Mayall's Bluesbreakers. Mayall told his producer, "He might not be better [than Clapton] now. But you wait... he's going to be the best." Soon, with the originalFleetwood Mac, he was Britain's most progressive blues guitarist, with a Chicago-informed aggression heightened by the melodic adventure on albums like 1969'sThen Play On. Green soon entered a dark age of mental and health problems, returning in the Nineties with more subdued but recognizable gifts.Key Tracks:"Albatross," "Rattlesnake Shake"

59Robbie Robertson

Gems/RedfernsWhenBob Dylandescribedthe Band's "wild mercury sound," he was really talking about Robbie Robertson's guitar, as exemplified by his torrid, squawking solo on "Just Like Tom Thumb's Blues" from their 1966 tour. But by the time the Band were making their own LPs, Robertson had pared down his approach, evolving into a consummate ensemble player. "I wanted to go in the opposite direction," said Robertson, "to do things that were so tasteful and discreet and subtle, like Curtis Mayfield and Steve Cropper... where it was all about the song."Key Tracks:"The Shape I'm In," "Like a Rolling Stone (Live 1966)"

60Ron Asheton

Richard McCaffrey/Michael Ochs Archive/Getty Images"My part is just a few notes over and over,"Iggy Poponce said aboutthe Stoogessong "TV Eye," "but Ron created a whole world around that." In Asheton's hands on proto-punk anthems like "I Wanna Be Your Dog" and "No Fun" the classic three-digit barre chord felt more like a superpowered battering ram: droning, relentless and almost mystical. (Asheton, who died in 2009, called it "those magical three fingers.") You can hear Asheton's wild-man approach all over the playing ofKurt Cobain, Thurston Moore andJack White.Key Tracks:"No Fun," "TV Eye," "I Wanna Be Your Dog"