This script will change the file type of the selected AAC tracks--which you have previously made bookmarkable yourself with the script Make Bookmarkable--to "M4A" and file extensions to ".m4a" making them UN-bookmarkable. When used with iTunes 7 or later, each track is deleted and re-added so that it will be removed from the Audiobooks Library. Ratings, play count, last played date, skip count, and skipped date are preserved.
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Remove iTunes tracks disassociated from files
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Set the Album Rating for the album of a selected track to full- and half-stars or computed clear-stars
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Sort purchased tracks into discrete playlists by name or Apple ID
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View/Edit tags of selected track(s) in single window
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Set current track's start or stop time to current player position
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Change file type to make selected AACs bookmarkable