First: I am not looking for bulk-updating a whole lotta files. No regular masstagger.
What I am looking for is something that
* scans a selection of files
* reports which ones have artist tag wrong - preferably, sorted by badness.
I mass-ripped my collection back in the day, with autotagging by the usually excellent dBpoweramp suite (which identifies by CD TOC). Thousands of discs.
And there are duplicate CDTOCs around, especially when it comes to singles. And since I had a lot of collections bought en bloc, including a lot of promos, the "listen to random unknown album of probably not so interesting quality and genre" ritual takes time.
I thought I had cleaned up most, but I just found one "lost" for ten years that was even a full-length album of twelve tracks, so ... heck, why don't ask. There could be such a tool around ... is there?
You might have a look at SongKong
It gives you a list op changes and you can undo them
A short impression: http://www.thewelltemperedcomputer.com/SW/Tagging/Songkong.html
Take a look at Picard, which uses the MusicBrainz DB: https://picard.musicbrainz.org/
Can Picard in any way indicate how bad my tags are? It surely can fail to match, but I don't want that.
I didn't know about SongKong. Will check.