>>916602
Picard is kind of shitty. Firstly, it's strictly interactive, and, secondly, it doesn't know how to accommodate inconsistencies in the Picard library.
I would recommend beets. It uses the Picard library but can take advantage of discogs api's, whose database is much more thorough. It's also significantly more robust and is highly extensible, as evidenced by its blossoming plugin ecosystem, including plugins for fetching and embedding album art from online search engines.