OS X 10.8 or later. This applet will assist with swapping, copying, and appending data between two user-chosen tags in selected tracks or tracks in the selected playlist:
Swap - swap data between tags, ex: ARTIST<->COMPOSER
Copy - copy data from one to another tag, ex: ARTIST->
Append - append data from one tag to the end of another, ex: ARTIST->COMPOSER - ARTIST
Prepend - prepend data from one tag to the beginning of another, ex: ARTIST->ARTIST - COMPOSER
The latter three actions also provide an option to delete the info from the first tag after the copy. Read Me explains all.
This update is free for registered users of v4.x.
Select the Action to perform between the two chosen tags in each selected track.
(via in-app purchase)
Perhaps Also of Interest...
downloaded 7m 33s ago
Remove iTunes tracks disassociated from files
downloaded 7m 35s ago
Export files of tracks in two or more playlists to single folder
downloaded 7m 54s ago
Set year of selected tracks to their release date's year (if available)
downloaded 17m 1s ago
Exports and then re-imports selected tracks' artwork
downloaded 19m 40s ago
Display, create text file listing info of dead tracks
downloaded 25m 35s ago
Displays files in iTunes Media folder not in iTunes track library