From 1967, with the song dubbed in a new stereo remix I made to expand the orchestral section! (...unlike the newly remastered "Magical Mystery Tour" CD!) This episode was inspired by the fact that the "Strawberry Field" of the song had been based on a real-life Salvation Army orphanage in Liverpool. When the Beatles stop by a dilapidated orphanage, the hostile attitude of the children (who are drawn in muted colors like the downtrodden Pepperlanders in "Yellow Submarine") is explained by the Beatles' driver, James, as being being due to their "sociological environment". So the Beatles set about to create an Elysian playground with song! John's "Musketeer Gripweed", of his film "How I Won the War", has a cameo! (Thanks, anti-wars!)

Note: John's final line, "It's all in the mind, y'know!" would be echoed by George in "Yellow Submarine", verbatim in a DVD-only scene during the coda of "All You Need Is Love", plus approximately quoted earlier in all versions of the film (and as well used in print advertising for the film).
Also: the slide seen is the "Helter Skelter" type, the kind that would itself inspire a Beatles song the following year! (less info)