Word for writing down an already known song

I'm looking for a suitable word to use if someone has written down a song let's say 100 years ago from a person who sung this song. In other words: Writing the sheet music for a song that is already existing.

In swedish we say that the song is "upptecknad". I'm working on a website where I will publish some old songs and I want to write when the songs where "upptecknade"/written down. It would not be suitable to use "composed" as the song was already existing.