Appellation d'origine contrôlée Portugal's Denominação de Origem Controlada, Austria's Districtus Austria Controllatus, South Africa's Wine of Origin, and Switzerland's AOC-IGP are all similar to the French AOC system as well. It appears also that AOC influenced the development of the European Union's protected designation of origin (PDO) system. Switzerland has an "appellation d'origine contrôlée" certification for wines and an "appellation d'origine protégée" certification for other food products. Before 2013, the "appellation d'origine contrôlée" was used for all products. The United States' American Viticultural Areas also follows the model set by the French AOC. The United States Department of the Treasury's Alcohol and Tobacco
What Shall We Do Now? song is the same backing track as "Empty Spaces", but in the original key of D minor. It's a slow, dark progression with a repetitive, electronic drum beat and solo guitar, but where "Empty Spaces" ends and segues into "Young Lust", "What Shall We Do Now?" moves into a second, louder section punctuated with guitar power chords. The transition of D - E - F - E is a recurring theme throughout the album, heard on "In the Flesh?", "In the Flesh", "Waiting for the Worms", and the three "Another Brick in the Wall" songs. The long verse is played