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.
Preview each track as it will appear after applying the entered text.
Perform search-and-replace on text in your choice of tags
Append user-entered text to beginning or ending of selected tag of each selected track
Set choice of various number tags of selected tracks incrementally
Edit a selection of iTunes tracks' tags in single window
Create a PDF booklet containing info from the selected tracks
Correct song titles listed as "Artist - Song Name"