What is the fine-grained topic of the following text: His brillant collaboration with Carole King in the musical Really Rosie, which was performed off Broadway and made into a television special and eventually into a DVD, took four of his stories (Chicken Soup with Rice, Alligators All Around, Pierre, and One Was Johnny), which were collectively known as the Nutshell Series, and brought them vibrantly to life. Only return the topic.
Collaboration of Carole King and Maurice Sendak in the musical Really Rosie.