Allman Brothers Band

Co-founder of the Allman Brothers Band was 80 years old.

He'd been suffering from cancer and chronic obstructive pulmonary disease.

"People may find that hard to believe, but it had never happened," Warren Haynes tells UCR. "It was history."

Deaths of Duane Allman and Berry Oakley still loomed in 1973.

New collection contains footage from surviving members' 2020 Madison Square Garden show.

Set includes material recorded by Grateful Dead's soundman at famous New York City venue a year before more famous shows.