Apple just released iTunes 126.96.36.199. The original installers can be downloaded from their site. The new switchless installers are on my server already. Remember to read the description page to learn about the modifications made. As usual, the links to the files are on the Custom Installers Downloads page. Enjoy!
When Apple released iTunes 11, many users complained that the more simplistic looking interface hide some of the most useful things like the sidebar and the main menu bar.
You can still have the sidebar displayed on the left of the screen, just follow this simple steps.