The magical world of the string quartet will come to life in a 45-minute program that introduces younger audiences to classical music in an interactive, engaging format. “Circle Unbroken” is a special adaptation of Margot Theis Raven’s celebrated children’s story about the history of the sweet grass basket. Music of the late African American composer, William Grant Still will be performed while the story is narrated and illustrations by E. B. White are displayed on a screen. A nursery will be provided during the concert. Musicians include Megan Allison and Frances Hsieh, violin; Katrina Smith, viola; and Timothy O’Malley, cello.