21. George Harrison
As the Beatles' lead guitarist, George Harrison never played an unnecessary note. In his solos and fills, he prized clarity and concision above all things. But every note made history, from the Cavern Club R&B frenzy of his breaks in "I Saw Her Standing There" to the hallucinogenic splendor of his contributions to Revolver and the matured elegance of his work on Abbey Road. John Lennon and Paul McCartney dominated the Beatles' revolutionary course through 1960s pop, but Harrison defined the musical character of those innovations in his explorations of studio technology, tonal color and Indian scales. At the same time, he never strayed from the terse, earthy qualities of his first love, 1950s rockabilly, and his biggest idol, Sun Records star Carl Perkins. Harrison's final album, Brainwashed — recorded in the years before his death from cancer in 2001 — features some of his finest twang.