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 - append 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 4m 28s ago
Display and export playlists' name, size, time, track count, love/dislike for selected source
downloaded 10m 15s ago
Set the Plays of selected tracks.
downloaded 14m 24s ago
Sort purchased tracks into discrete playlists by name or Apple ID
downloaded 20m 45s ago
Gather audio tracks whose files contain no artwork metadata
downloaded 23m 43s ago
Exports and then re-imports selected tracks' artwork
downloaded 42m 35s ago
Displays files in iTunes Media folder not in iTunes track library