As in songs that are actually present in the world of Runeterra.
We know that these exists like "[The Path to Hearth-Home](https://youtu.be/e47AEBnu9SQ)", Ornn's teaser song which is sang by Layka, Nunu's mother.
Consequently we can imagine that it is a traditional song from the Freljord or at least from the Notai Tribe, and considering the Notais are/were known for their dances and musics, it is safe to assume there's more.
Each region have its own personality, instruments and characteristics and considering music is an universal language, every region and races must have their own take on traditional songs.
Have an album regrouping songs from different parts of Runeterra ever been considered?
Honestly it would be awesome on a worldbuilding standpoint.