‘Sesame Street’ changed the world of children’s television when it arrived on our screens in 1969. The programme’s inception came from the unique collaboration between TV executives and child education specialists, and always had diversity at its core. A new documentary, ‘Street Gang: How We Got to Sesame Street’, tells the story of the show. Robert Bound speaks to the film’s director, Marilyn Agrelo, about what makes ‘Sesame Street’ so iconic.