I tried to change the information (cover, album, artist, etc.) of some songs, just double clicking on "information" of any file. I can't change any of them in this way, even if I enter like admin; the only way to change the information is with iTunes, but the information changed is not changed in the user directory.
When I try to play a song with iTunes, automatically any songs are copied in Music → iTunes → iTunes Media → Music. Even if I delete the music files in my user folder, they remain inside the iTunes directory.
Why does this happen? Doesn't make more sense that iTunes copy the link instead than all the file? In this way 2 copies of each files remain on the machine and the memory will be full before for no reason.
How can I change the information on each song in my user folder if double clicking on "information" of any file doesn't change anything?