They didn’t write them down at all. They remembered them.
In their early years, Lennon and McCartney wrote songs together and one of their rules was that if they wrote a song but then couldn’t remember how it went, they’d junk it. Since they were trying to write songs that were catchy, this rule worked very well. They wrote words down and changed them on the page, and they might scribble guitar chord names above the words, but as far as the tunes and guitar parts were concerned, they just remembered them.
Later, when their songs were going to be published, they were .....
Hi and thanks for taking a look. If you have a email you want to share with us the please contact us by clicking https://www.hifianswers.com/talk-to-our-editors/