OS X 10.8 or later. Append the same user-entered text to the beginning or ending of the existing text in the chosen tag (Song Name, Artist, Album Artist, Album, Composer, Comments, Genre, Grouping or Show Name, and their Sort siblings) in each selected track.
For tags other than "Song Name" and "Show Name", this script may be just slightly less involved than performing a multi-edit on the selected tracks.
Also see This Tag, That Tag.
Preview each track as it will appear after applying the entered text.
Remove iTunes tracks disassociated from files
Export artwork of selected tracks to parent or specified folder
Export Playlist names of selected Source to text file
Exports and then re-imports selected tracks' artwork
Capitalize the first letter of each word in selected track names
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags