The tracks "Celebration Song" and "My Dark Hour" featured Paul McCartney (credited as "Paul Ramon") on backing vocals, drums and bass guitar. "My Dark Hour" was recorded in a late-night session on 9 May 1969 after McCartney had had an acrimonious argument with John Lennon, George Harrison and Ringo Starr over signing a contract appointing Allen Klein as The Beatles' financial manager. Miller was the only member of the band to attend the session, and the song emerged from him and McCartney jamming.
The primary guitar riff on "My Dark Hour" was also used on the title track to Steve Miller's 1976 album Fly Like an Eagle.
"Space Cowboy" uses the same primary guitar riff as the Beatles' song "Lady Madonna," owing perhaps to McCartney's involvement on "My Dark Hour" and allied permission. It was released as downloadable content for the video game Rock Band on January 20, 2009.
^Morthland, John (26 July 1969). "Records". Rolling Stone (San Francisco: Straight Arrow Publishers, Inc.) (38): 37. Archived from the original on 2 Oct 2007. Retrieved 10 September 2015.
^Castleman, Harry; Podrazik, Walter J. (1977). "1969 – "But If Paul's Alive, How Did He Die?". All Together Now – The First Complete Beatles Discography 1961–1975 (Second ed.). New York: Ballantine Books. p. 78. ISBN0-345-25680-8.|access-date= requires |url= (help)