OS X 10.10 or later. iTunes only allows one playlist to be selected at a time. This applet can perform common useful tasks on a multiple selection of playlists: rename (add text, remove text, search and replace text), duplicate, delete, export, merge.
Tools in the Rename tab operate on the selected playlists' names
(via in-app purchase)
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downloaded 25m 1s ago
Exports and then re-imports selected tracks' artwork
downloaded 29m 30s ago
Title Cap various track tags, featuring editable exceptions lists
downloaded 30m 50s ago
Change case of selected track names to sentence caps
downloaded 1h 12m 58s ago
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
downloaded 1h 32m 29s ago
Renumber order of selected tracks
downloaded 1h 59m 21s ago
Export selected playlists as individual XML or M3U files