Apart from the giant yellow bird, the red furry monster and the blue Muppet with an insatiable appetite for cookies, “Sesame Street” appears as real as the New York City streets that inspired it.

Come and play, everything’s a-okay. You only have to hum a bar or two of the “Sesame Street” theme song to become instantly nostalgic for watching some of your favorite characters — Bert and Ernie, ...