Are members of Monty Python on the Beatles’ “Yellow Submarine”? I’m almost certain it’s Graham Chapman echoing Ringo in the third verse.

The guests singing in the chorus and adding sound effects did not include any Pythons, but did feature Brian Jones of the Rolling Stones, Marianne Faithfull, and Pattie Harrison (of “Layla” fame); to produce water noises, John Lennon blew bubbles through a straw in a bucket of water. In 1966, when “Yellow Submarine” was recorded, “Monty Python’s Flying Circus” was still three years away. The Beatles were big fans of the show, though; Paul McCartney would stop recording sessions so he could watch, and George Harrison ended up producing several Python films, including Life of Brian. (Also a Python watcher: Elvis Presley, who apparently got into the habit of calling people “squire” from Eric Idle’s “nudge-nudge” sketch.)

(Excerpted from the 2006 book Is Tiny Dancer Really Elton’s Little John?: Music’s Most Enduring Mysteries, Myths, and Rumors Revealed, published by Three Rivers Press, written by Gavin Edwards.)