The 1968 animated film of Yellow Submarine is inextricably linked with the Beatles – not just their music but their imagination, ideas and identity. But, with the exception of one scene to meet a contractual obligation, the voices of the band featured in the film were provided by actors and not John, Paul, Ringo and George. It later emerged that John Lennon in particular was unsatisfied with the creative involvement the band had and not receiving credit for the ideas they had provided for the film.
YouTube channel Beatles Bible recently cast Lennon's views on the film in a stark light – using audio from The Lost Lennon Tapes radio series that features Lennon's 1980 interview with David Sheff for Playboy, he doesn't hold back when talking about the background to the exclusive song the Beatles provided for the film's soundtrack; Hey Bulldog. He described the people involved in the film as "gross animals" – with the exception of artist Alan Aldridge, who had first illustrated the Yellow Submarine in November 1966 following the Beatles' Revolver album.
Source: Rob Laing/musicradar.com