I share my whole iTune library, well keeped: songs, singers, albums name, artworks etc..
But did someone have looked in the LW shared library ? Is a mess... duplicate title ( Named differrently indeed, but where LW got those name ?) ... Some classified by singer, some by song titel... "Unknow album" when album name is the same as a song title... Till 3 albums created for one single album with only few title in each...
I can delete, move or rename title but how to delete empty folder ?

No you don't need to delete the folders!!! Either within iTunes or another mp3 app. change the id tags. Within iTunes just select the tune on the main playlist, Command (apple key) & i (OR go to iTunes menu choose File>Get Info), & then correct the details of id tags for the artist & album, etc. When you exit that window. You'll find that the tune now has the adjusted name & info. Double-click on that tune & iTunes will make the adjustments to its library by itself. It will move the tune to a new location under the correct artist & album name. And the previous unknown folder will disappear. Likewise if you change the id tags within another mp3 app, then the next time you open iTunes, likewise double-click that tune & iTunes will make the adjustments to its own library. So don't attempt to move/delete files manually in the Finder. Do it properly within iTunes.

... thank u my Lord !

thank for u advise... I wont try anymore, only now i have few empty folder ( renamed empty f.1/2/3...) cause i move manually some songs to the folder i though right...
BTW, seems that the LW library and the iTune library look exactly the same ! I dont understand the logic of it ! F.ex. some number of Buddha Bar cd are classified in different folder, some are even classified as complilation other not !? ( Am talking of one single CD )

If you have LW copying directly to itunes then yes, you'll end up up duplicate files. You can use the LW dwnld files as backup or whatever. Keep the iTunes files & folders which you've put a lot of work into organising as your main priority. So you can burn from these or whatever you like.