Featuring the twin lead guitar beauty of Betts and Duane Allman, with Gregg Allman on lead vocals, “Revival” became the first Allman Brothers song to chart on the Billboard Hot 100.

The mythic figure at the center of the Allman Brothers was Duane Allman, the redheaded guitar genius who ignited the recording sessions for Eric Clapton’s “Layla,” who played slide with an ...