This script checks your entire iTunes library for missing and presumed dead tracks--those tracks that iTunes is unable to associate with a file and which are listed in iTunes with a "!"--and can create a text file listing these tracks by alleged File Path (if available), Song Name, Artist and Album, which you can view using TextEdit.
OS X 10.6 and later only. Universal version for PowerPC machines available at the link below in the "Info" section.
Also see Music Folder Files Not Added
To find and delete dead tracks see Super Remove Dead Tracks.
See the video on YouTube.
iTunes can't find the files pointed to by the Location property of these track entries.
Remove iTunes tracks disassociated from files
Copy Artist to Album Artist of selected tracks
Perform search-and-replace on text in your choice of tags
Exports and then re-imports selected tracks' artwork
List tracks not assigned to playlists
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags