Eli5 How did classical music composers memorize their songs back then after creating them?

Question

Let’s take for example the nocturnes of Chopin.

My preferred one is nocturne n. 20

He certainly didn’t have studio machine to record their sound AFAIK

How then did he memorize and write down everything to remember later?

Did he start playing the piano, write down the notes, continue playing or did he memorize the whole song by heart without any writing process?

Sorry 4 my bad English btw. Not a English native speaker.

EDIT : thanks everyone for the explanation.

In: 157

Answer 1

The answer is in your question.

How then did he memorize and ***write down everything*** to remember later?

They wrote it down. If you have notes and documentation you refer to those it was the same back then as it is today.

They referred to their notes, which were often organized, and voila they could continue to compose and adjust. When they made an adjustment they’d write it down and make a new note. The good thing about the written word is it preserves thought.