- If there has been no changes in any tags for a track, then "Tag History" context menu command for that track should be disabled. That disabled state itself is a useful information to the user.
- If there were changes, show those tags and values only on the popup window upon clicking on the command. Something like this would suffice, really no need for fancy visual clutters.
The example shows previous values of Title and Album Artist along with when each value was updated.
If the user right-click on one of the previous values, context menu shows "Copy" and "Restore" command. With copy, the user could paste it on a notepad and edit the value (and then could copy and paste it using MB's tag editor). With restore, the plugin overwrites the current value with the selected value.
- Some tag values can be very lengthy (e.g. classical music) and multiple selection of cells needs to be supported. Maybe clicking on a column header could select all tag values on that day like Excel.