Even those resistant to easy nostalgia will find plenty to think about. As told here, the show’s strategy — using television’s methods for teaching children beer jingles to teach them the alphabet instead — could only have come together through a combination of figures: Joan Ganz Cooney (a creator of the show and the first executive director of the Children’s Television Workshop); Jim Henson, who brought Muppets and just the right amount of irreverence; and the workhorse director-writer-producer Jon Stone, whose daughters say he treated the show as his third child. The show required the input of educators and psychologists and owed some of its freedom to experiment to federal investment.

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