iTunes has exactly one way to organize, and that is by artist/album.
If that is not what you prefer, then go into Preferences > Advanced, and make sure that "Keep..." and "Copy..." are both not checked. Then, for any new songs you plan to add to iTunes, put them in whatever folder you want them to be, and iTunes will be reference their current location, and will not move or change anything.
BTW, changing those settings will give you the correct handling of new additions, but will not change anything that is already in the library. Also, it does not affect any future items purchased from the iTunes Store.