For macOS 10.10 and later. This applet will allow you to view and edit most tags (and some additional options) of the selected track(s) in a single floating window using single-edit mode (one selected track) or multi-edit mode, which emulates the pre-iTunes 12 "multiple items" format; that is, a checkbox adjacent to each tag allows you to select which changes are to be applied to the selection's tags.
Can also be used to copy collected tags from one set of tracks to another set of tracks by toggling "Information Tracking".
Thanks to Wolfgang Reszel for the icon.
Access most tags of a selection of iTunes tracks in a single window. (Sorting tags are accessible via togglable Drawer.)
(via in-app purchase)
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