Resolve an album/release from MusicBrainz (CC0). Pass a barcode (UPC/EAN), or artist + album, or a free-text query. Returns ranked releases with MusicBrainz ID (MBID), title, primary artist, release date, country, barcode, status, track count, label, and catalog number. Keyless, public-domain core data. Barcode → album is the differentiated lookup (resolve a physical product to its metadata).