Paul McCartney's first version of 'Yesterday' was a tune with no words. So he created placeholder lyrics "to remember the timing of the words ... That's how you remembered the song," Jimmy Fallon confirmed when the former Beatle appeared on 'Late Night' (weeknights, 12:37AM ET on NBC).

The host then coaxed McCartney into performing -- for the first time ever -- the original "Scrambled Eggs" rendition. The duo crooned (with straight faces): "Scrambled eggs / Oh my baby, how I love your legs / Not as much as I love scrambled eggs / Oh we should eat some scrambled eggs."

Another verse pined for waffle fries, and another concerned "tofu wings" -- since McCartney is a vegetarian. Obviously, not all of those lyrics are historically accurate... Check out the whole hilarious song (and Fallon's decent harmony) here.