Apple seems hell-bent on making iTunes as painful to use as it can, and iTunes 12 really drives that point home by killing the Library and playlists sidebar. There is a way to bring the sidebar back to life and take away some of the sting that's the iTunes 12 interface.
This is no way to experience iTunes
The default album view Apple pushes in iTunes doesn't do much for me, so the first thing I did to make the app bend to my will was click the Albums drop down menu and choose Songs. That ditches the album view in favor of the old-school song list. Then I chose Column Browser from the iTunes View menu so I could see my Genres, Artists, and Albums columns above the list.
Use the Albums dropdown menu to switch to the song list view
Once I gave a more familiar look to iTunes I clicked the Playlists tab to show the old and familiar Library and playlists sidebar. With that, iTunes 12 felt a lot more like iTunes 11, which still wasn't the greatest but at least was usable.
Less flashy, but more useful: My sidebar, plus music list and columns
Here's hoping Apple has plans to start over with iTunes and give us an app that's easier to use.