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.
App displays files in iTunes Media folder which are not in iTunes library
Perform search-and-replace on text in your choice of tags
Remove iTunes tracks disassociated from files
Export artwork of selected tracks to parent or specified folder
Applet assists with swapping, copying, appending data between track tags
Copy Artist to Album Artist of selected tracks