Terry Knight, best known as the manager for Grand Funk Railroad, recorded the song "Saint Paul" in 1969 that may have started the great wave of "Paul McCartney is Dead" rumours of the late 1960s.
Here's the song, spliced to footage of a Beatles performance of Hey Jude (which the writer of Saint Paul liberally cribs from!):
(I'm more familiar with the cover version by Shane, which was a monster hit in New Zealand.)
You may see the Shane version here:
If all this interests you, I suggest that you read the fascinating book I Am The Walrus, which examines the history of the rumour.
(The late Mr. Knight, when asked whether he knew that the song had contributed to the rumour, is reported to have smiled and said "Yes, I'd heard that...")