The Tumblr EMOCTV collects instances in which forward-thinking music turns up in children’s TV shows — everything from Mr. Rogers demonstrating an ARP synthesizer, above, to art-rock veterans The Residents performing on the Chicago public access program Chic-a-Go-Go. It’s all worth perusing, but the highlight is an episode of the French TV show Angelo Rules called “The Experimental Music Must Be Stopped,” in which the title character tries to dissuade his mother from listening to so much avant-garde weirdness.