Four Folders: The first thing I did was go to ~/Music/iTunes/iTunes Media/Automatically Add to iTunes/ and dragged it to the toolbar in Finder. As the name suggests, anything dragged to that folder will automatically get added to iTunes. I renamed my old iTunes folder to "Old iTunes" and moved it back to my ~/Music folder; I dragged it back to my Finder toolbar also. I created a new folder called "Check Later," which is where I would put any music that I wasn't sure I wanted to keep or throw away. That went to the Finder toolbar, too. Finally, I used Finder's "Go To Folder" to navigate to ~/.Trash/ and dragged that to the Finder toolbar as well. This made it easy to trash anything that I knew I didn't want to keep. Now, I had four easy-to-access folders for anytime I wanted to spend some time cleaning up my iTunes library. (You can see a screenshot of this above. To add a folder to your Finder toolbar, just drag it to an open part of the toolbar.)
I went into iTunes' Advanced preferences and made sure that "Keep iTunes Media folder organized" was selected as well as "Copy files to iTunes Media folder when adding to library." I used the Search field in Finder to locate files that ended in .m4a, .mp3, .m4v, and any other music or video related extension I could think of, and then I set them to open with VLC instead of iTunes. I wanted to make sure that nothing went into iTunes unless I specifically requested it.
Careful Rebuilding: Now, I was ready to begin rebuilding. With iTunes running, I went into my Old iTunes folder and searched for the names of bands that I knew I wanted to add back in: The Who, The Doors, Diana Krall, U2... and already I stopped. I've been a fan of U2 since the early 80s, but they went through a weird period in the 90s where they put out several CDs that I bought, but didn't really enjoy as much. So, I dragged only the albums that I knew that I wanted or, in some cases, the songs that I wanted, to the Add to iTunes folder.
After I added a few albums, I switched over to iTunes to check the information shown. Were the songs labeled correctly? Did I have more than one copy of the same song? I added the "Bit Rate," "Size," and "Kind" columns to iTunes so that I could easily compare duplicates. Since I was dealing with just a few at a time, it was relatively painless. When I got bored, I did something else and just enjoyed listening to my music collection for awhile. In a future article, I'll tell you about the various apps that I tried to clean up metadata and add cover art.
Other Options: Most people may not want to go through such a severe manual purge and restore. There are a couple of other options that I tried but ultimately abandoned.
Option #1: Uncheck songs. Next to each song in your iTunes library is a checkbox. You may not have ever paid any attention to it; I never did. But you can make Smart Playlists that will "Match only checked items." You could try un-selecting songs and building selective playlists using those.
Option #2: iPad, iPod specific playlists. My original intention was to just build specific playlists for my iPad or iPod, but there was just such a mountain of songs that I knew I was never going to want to listen to, it seemed like a better idea to start with a clean slate.
Have you done a major overhaul of your iTunes database? Let us know what you did in the comments.