I have gone through a few hundred songs, but forgot to add/change the artwork. Not sure why the program doesn’t do it when it changes the tags, but done is done. So, is there a way to match the songs I’ve already done (they all have the MusicBrainz ID’s) and get the artwork added, automatically?
Yes. If they have already been tagged with MusicBrainz IDs you can load them back into Picard and Picard will automatically load the corresponding release in the right pane and match the files to it. Just make sure you have not checked Options > General > Ignore MBIDs when loading new files.
As for cover art take a loo at the settings in Options > Cover Art. You have to enable at least one cover art source and choose whether you want to save the cover art in the tags, as files or both. Also there are plugins that provide additional cover art sources (currently there are Fanart.tv, TheAudioDB and Amazon).
Thanks. I hadn’t chosen any sources.