"Sesame Street" first aired in 1970 on PBS, where it continues to be available for free. It entered into an agreement with HBO nearly 10 years ago to air new episodes before they premiered on PBS.

Sesame Street is 50 years old. From the Bronx to Bangladesh, the impact of the playful puppets of Sesame Street has spread far and wide over that time. The BBC's Laura Trevelyan hangs out with ...