Class One of The Art of Influence opens with The Wizard of Oz—how Production Designer Cedric Gibbons and Set Decorator Edwin B. Willis built Oz from the ground up. I unpack the sepia-to-color switch, Munchkinland’s circular plan, the Yellow Brick Road as a story spine, Emerald City’s Art Deco vocabulary, the Wizard’s forced-perspective corridor, and why the sets still feel alive today. This episode is free; the full masterclass—covering MGM’s greatest builds and their ripple effect on modern film and TV—is available on my site.Keywords: Wizard of Oz, production design, set decoration, Cedric Gibbons, Edwin B. Willis, MGM, Technicolor, Emerald City, Yellow Brick Road, Munchkinland, classic Hollywood, film design, set decorator, art direction, film history, visual storytelling.