Can you rename my music libraries without breaking Apple Music on my iPhone?

Trying to help my son with a problem. He has 2 Apple Music libraries: the default "Music" and a new "Local". He has a large number of other files and folders in the top-level Music folder. He would like to rename both of his music libraries to: _Music and _Local, so they show up at the top. Is this possible, and if so, how would he do that (on his Mac)? Thanks.