iT Library Clinic 1.0
Library Clinic is an iTunes® library assistant used to edit and manipulate the tag content and file locations of files listed in the iTunes library. It offers a more powerful and versatile tag editor and file renamer than the corresponding tools found in iTunes, plus it makes it easy to move specific files, or even a whole library, to another location without confusing iTunes. Use it to make multiple, alternative versions of your library, then activate the one you're interested in at any particular time. You can "catch up" libraries with corresponding tag changes, or tags with library changes, with just a single mouse click. It also contains an integrated playlist editor.
Library Clinic doesn't work directly on the iTunes library itself, but instead works on a copy of iTunes' backup file (XML file) in memory. Changes you make are not applied to the actual library until you tell it to, or until you allow it to. When changes are applied, a backup of the original library is created which can be restored at any time.