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)
Perhaps Also of Interest...
downloaded 2m 38s ago
Copy chosen tag info from one set of tracks to a different set of tracks
downloaded 4m 7s ago
Title Cap various track tags, featuring editable exceptions lists
downloaded 26m 40s ago
Set Last Skipped date of selected tracks to today or today minus your number of days.
downloaded 30m 37s ago
Delete files downloaded and cached by Apple Music
downloaded 32m 13s ago
Export selected playlists as individual XML or M3U files
downloaded 33m 16s ago
Remove iTunes tracks disassociated from files