The shows Elvis in relaxed mode during his 1968 comeback. The guitarist is Scotty Moore.
Peter Guralnick wrote an acclaimed two-part biography of Elvis. The second volume (Careless Love: The Unmaking of Elvis Presley, 2000) is one of the saddest books imaginable. Elvis comes across as a decent guy who was just unable to deal with what he had become. It gets grotesque, mentally and physically, towards the end. I’m sure the basic themes are similar in the fall of Michael Jackson.
The first volume of Guralnick’s bio is Last Train to Memphis: The Rise of Elvis Presley (1995).