When I look the Mp3tag window, it is filled with strings... and most of them are identical!
The idea would be to have an alternative way to edit and check the tags.
Based on %album% tag or directories, a single line could summarize an album.
Columns could display tag values and allow their modification and thus all tracks in the album/directories would be updated in a single step.
In a second step, when a line would be clicked, it could be expanded and its tracks displayed!
At last and optionally, Albums' art could be displayed for each line ;-)
PS: Mp3tag is really a great application!