November 29, 2012, 8:52 PM — Here's how you can restore the sidebar in iTunes 11.
1. Open iTunes.
2. Click the View option in the iTunes menu.
3. Select the Show Sidebar option.
Voila! The sidebar is back in iTunes 11.
For more, see the original article at the link below.
How to Restore the Sidebar in iTunes 11 | Mac Observer