Johanson came up in the R&B world and began drumming at an early age, often accompanied by friend Lamar Williams on bass. Johanson backed soul singers, including a membership in Otis Redding's touring band in 1966, and afterward touring with the acclaimed soul duo, Sam & Dave. After joining up with Duane Allman in February 1969, he quickly became the first recruit into Allman's new group, soon joined by bassist Berry Oakley, fellow drummer Butch Trucks, guitarist Dickey Betts and lastly Allman's younger brother, singer, organist and pianist Gregg Allman. The group, quickly named after the brothers Allman, began recording demos that April in Macon, Georgia, which became the group's spiritual home.
The band's mixture of blues, jazz and rock, spearheaded by the dual lead guitars of Betts and Allman, and the double-drums of Trucks and Jaimoe, were unique at that time, and they rapidly became known as an act that "you had to see live"