I have a suggestion that I think could be usefull to many people.
I use all my music from network share, and speed is not ideal when using programs like mp3tag.
I would suggest adding action queue, so when you do a large action that takes like 5 minutes to complete (e.g. change artist on 1000 songs) you dont have to watch the progress bar fill, you can continue editing stuff, and program does long action in background, showing you only percentage of completion.
You could then also add more actions to queue as you perform them, GUI would show you the result, but actual changing of data would happen in background.
Also reading of data could be done in background, filling list in groups of 100 (or 10) as they are read, so you can start clicking right away, without waiting for all thousands of songs to be read first.
Thank you for taking your time to read and consider this