There may be a way to organise a library in place but I’m not home until tomorrow so can’t check at the moment

Ah interesting point, I’ve only done this when importing new songs, not to an entire library. Usually drag my new files from a file browser into a new playlist then I select then all and right click, then hit “move to library” which brings up a dialog that allows you to define your folder structure and naming conventions

I use Strawberry for managing my music library. Easily organises files into directories and can manage multiple different libraries (I have separate libraries for music I want to dj with and music for general listening)