Some time ago, I discovered that you could enable half-star ratings in iTunes with a simple Terminal command¹:

defaults write com.apple.iTunes allow-half-stars -bool TRUE

Ever since I enabled that, I’ve been happily half-starring items.  When your music library runs to well over 40k songs, there is a difference between a five-star song, a four-and-a-half-star song, and a four-star song.

But then, sometime after I upgraded to Mountain Lion on my work computer, I noticed that all of my half-stars were gone.  My heart skipped a beat: I’d put a fair amount of work into rating those songs, and the idea of having to go back through and re-doing it made me quite cranky.  But I love my half-stars, so I quit iTunes, ran that Terminal command again, and re-launched it.

And then, I discovered that all of my half-star ratings were back.  Apparently those half-stars weren’t lost, they were just truncated when the correct bit wasn’t flipped.  Which means I can stop flipping out.

So, if you ever find yourself in my boat, try re-enabling half-stars with the Terminal command above, and see if iTunes does the right thing.  I hope it does.