Replying to Renaming songs in iTunes

ok, so i got the new itunes (but it was doing this with the old one), and when i go to change a song or album or artist name it lets me, but then once i play it it goes back. Like i downloaded a torrent for cypress hill, and for some reason one song had no info. I changed it to how it should have been, but once i played it it went right back. it does this with multiple songs/albums. anyone know how i can make the changes permanant?