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 7m 31s ago
Remove iTunes tracks disassociated from files
downloaded 15m 23s ago
Display, create text file listing info of dead tracks
downloaded 53m 23s ago
Convert selected tracks and export the converted files to a new folder
downloaded 55m 34s ago
Swap the name with the artist of selected tracks
downloaded 1h 30m 20s ago
Set choice of various number tags of selected tracks incrementally
downloaded 1h 31m 53s ago
Batch set new Last Played/Last Skipped of selected tracks