Paul McCartney's classic song "Yesterday" (1965) -- voted the most popular song of the 20th Century in a 2001 BBC poll -- had music long before the lyrics were written.. The melody came to McCartney in a dream. He brought it to John Lennon, unfinished, with nonsense lyrics as a place holder: "Scrambled eggs, oh my, baby, how I love your legs." The song became a standing joke between them for days while they tried to find words to fit the melody.
[McCartney finally wrote the lyrics during a three-hour car trip from Lisbon to the south of Portugal which he took with his girlfriend at the time, Jane Asher.]