I followed the instructions for moving my music (https://discussions.apple.com/message/9118646?messageID=9118646#9118646) as my C Drive was to capacity and my music files were doing it. However, after completing and reopening ITunes I have several issues:
1) Lost all my playlists
2) Some of my music files are missing but when I go the new location on my D Drive (all are in the same music folder) and double click....by track, I might add, they return to ITunes.
3) When I connected my iPhone 4 to add some music files, all the settings under music are "gone" and it's as if I was doing this for the first time. I'm asked if I want to delete all the music, etc. files on my phone and re-sync.
Hoping someone might be able to shed some light on this as I foresee a lot of time to be invested to get back to where I was before moving the files. BTW, all the library files were moved, too, AND everything moved is still in my Recycle folder so not deleted as I want to make sure everything is right before I do the delete thing. Besides.....I'm backing all the music onto a portable hard drive for safe keeping.
Ideally you would have moved the entire iTunes folder as a unit, then held down shift as you launched iTunes, holding until prompted to choose or create a library, used the choose option and opened the library in the new location.
Perhaps this method is still available to you. If not see Recover your iTunes library from your iPod or iOS device.