Bill Ward (Black Sabbath)
Somehow Bill Ward fused bebop and heavy metal before heavy metal was even invented. Wait… Did I mention that Bill Ward co-founded metal as a genre? With Tony Iommi at his side, and Ozzy standing somewhere within a mile of them, these dudes created an art form that may never die. If you've ever listened to a metal band at any point in your life, the reason the drums sound the way they do is because of Bill Ward.
Jim Keltner
Another studio musician who deserves more credit. Keltner worked with every Beatle’s solo project, Bob Dylan's “Knocking on Heaven’s Door” and Steely Dan’s “Josie.” Unfortunately, we'd run out of space explaining everything he's done, just know he was an incredibly important character.