Add a feature that will allow editors to associate artwork with a specific medium/mediums within a release. A single piece of artwork can be associated with multiple mediums. The artwork would be viewable in the Cover Art tab, just as it currently is.

Eventually support should be added to Picard to tag tracks in different mediums with the appropriate artwork, and not just the first piece of art that's happens to be listed as a cover. The medium associated artwork could also be displayed as a thumbnail in the release view on MB itself.

The default mediums to add a piece of front cover artwork to would be any that don't already have cover art (so in a new release, any added cover art will automatically be applied to all mediums, emulating the existing functionality). You should be able to edit the associated mediums using tick-boxes or something like that, at the time when you're adding the artwork, and also afterwards if you edit the artwork.

Several editors agree with this, and we've identified a short list of examples of releases that would benefit from this:

• The Beatles in Mono - http://musicbrainz.org/release/5cd103c6-07e3-32b1-8cea-7e53eb994829
• Brain in a Box: The Science Fiction Collection - http://musicbrainz.org/release/d962f518-d404-43f2-8c04-420f01fa5995
• The Complete Star Wars Trilogy: Original Radio Dramas - http://musicbrainz.org/release-group/43644e4e-cfd2-4f8e-b962-aa96206f733e
• Eric Clapton, "Crossroads" - http://musicbrainz.org/release/4f34e8a2-fc31-4972-acbb-dd5af6d59d10

See the attached sample image if you're still unclear!

Note: This ticket should share UX with/needs to be considered together with per-track artwork: https://tickets.metabrainz.org/browse/MBS-13789