iTunes 11 brings a lot of visual enhancements but there’s one change many users already don’t care much for - the lack of a sidebar. Luckily, there’s a fix.
When you upgrade to iTunes 11, you’ll notice that quite a lot of your stuff has been relocated or downright eliminated from its interface.
Don’t worry, your music, movies and apps are still there on your hard drive. The only difference is that iTunes 11 displays all of them in a different manner, and in very different places.
If you’re having a rough time adjusting to the single-pane interface, just hit View in the menubar and select “Show Sidebar.”
iTunes will now display your beloved left pane listing music, movies, TV shows, books and apps as before. Connect an iDevice and it will also show there. Your former playlists should also be intact.
Hope this helped.