Change the case of the selected iTunes track names to "sentence case": all lowercase with the initial letter uppercase. For example, "L'effet Que Tu Me Fais" could become "L'effet que tu me fais", and "Comme D'Habitude" becomes "Comme d'habitude". This is customary in many languages.
(Note: In order to launch this PowerPC-era script on an Intel machine, it must first be opened and then saved using AppleScript Editor, which is located in your /Applications/Utilities/ folder. More information is here.)
Remove iTunes tracks disassociated from files
Display, create text file listing info of dead tracks
Change file type to make selected AACs bookmarkable
Copy number prefix in Song Name of selected tracks to their track number tag
Perform search-and-replace on text in your choice of tags
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags