I am shocked that no one has mentioned Steve Cropper. Have memories become that short? Cropper and his bassman Duck Dunn were the driving force behind the gritty southern soul of the Stax recordings in the 60s and 70s. George Harrison once remarked that Cropper was his favorite guitarist. He was the ultimate session man.
Speaking of session guitarists who gave us California pop in the 60s and 70s the Wrecking Crew is still largely unknown to the general population. Their guitar licks still reverberate across radio daily and everyone here knows their work... just not their names and what they did for American music. Easily a quarter of the songs heard on the radio then were the work of these greatest of session guitarists and other musicians.