"When we came, it was quite shortly after Kennedy being assassinated," Paul McCartney says in the trailer, released Thursday. "Maybe America needed something like The Beatles to be lifted out of sorrow." McCartney and Ringo Starr are among the documentary's producers, while David Tedeschi serves as director.

Then, a press release issued by Paul McCartney in April of that year confirmed he would no longer be working with The Beatles, bringing an end to the hope they would carry on without John. Paul's departure led to a bitter row about the releases of 'Let It Be' and Paul's first solo album - 'McCartney'.