This script recursively searches user-selected folders for files not added to iTunes and creates a text file listing their file paths. Optionally, this text file can be saved as a M3U file and imported by iTunes to add the found files. Requires Mac OS 10.4 or later.
You will probably prefer the more modern Music Folder Files Not Added.
OBLIGATORY WARNING! Because this script has been designated as a "Retro Script" there is no guarantee that it will function as described and may even corrupt or destroy data.