This script converts the files of the selected tracks in iTunes using an encoder of your choice on-the-fly (restoring your Preferences-set encoder afterwards). The newly converted files are then moved to a new location of your choice, and their tracks removed from iTunes.
OS X 10.6.8 or better.
Also see ConvExp to Album Folders.
Display, create text file listing info of dead tracks
Remove iTunes tracks disassociated from files
Set choice of various number tags of selected tracks incrementally
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Set the Plays of selected tracks.
Locates pairs of track entries pointing to the same file