This script will apply the same user-entered text to the "Description" tag of each of the selected tracks.
iTunes 12 no longer provides a way to edit the Description tag of tracks in the Get Info panel for a multiple-selection of tracks.
The text you enter will be applied to the "Description" tag of the selected tracks.
Paste non-ID3 Tag track and file related info into Category, Comments, or Description tag
Edit a selection of iTunes tracks' tags "old-school"
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
Re-populate selected Smart Playlists
Export files of tracks in two or more playlists to single folder
Set the Plays of selected tracks.