I've looked at Picard and it's clutzy. Mp3tag free, drag 'n' drop in any art you want. Manage tags easily for folders.
Batch conversion I recommend XRECODE3. It was free 10 years ago. I donated then because it was so good. Best $15 you'll ever spend. Or €10.
Batch conversion I recommend XRECODE3. It was free 10 years ago. I donated then because it was so good. Best $15 you'll ever spend. Or €10.