Dave, they are just in a word processor, like MS Word. Now Libre.
I can sort by name, artist, genre...
I actually have two sets. One is in .doc format, the other in .txt format. I use the text files on the arrangers, since they won't read .doc. Can't sort on the arranger, but you can make various folders, like Christmas, Oldies, Standards, etc., if you want.
It has taken me about 50 years to build all this. It would be much easier to do it now.
Not sure I'm ready to share the entire thing, but I will gladly share individual songs.