Ella Jenkins, a singer-songwriter known as the “first lady of children’s music ,” has died. She was 100. According to  NPR , John Smith, the associate director of Smithsonian Folkways Recordings, confirmed news of her passing. Jenkins had an enduring relationship with the  nonprofit record label , recording 39 albums throughout her career of nearly seven decades.  Finding her unique sound by way of church, folk and schoolyard influences, Jenkins, who was a self-taught musician with a natural understanding of rhythm, built a career on writing and performing music exclusively for children, a rarity in the mid-20th century, according to  The New York Times . Her infectious renditions of nursery rhymes like “Miss Mary Mack” and “The Muffin Man” played a pivotal role in redefining children’s music and showed how music could be a tool for learning and empowerment.  Jenkins’ career began in the 1950s when she quickly became known for her signature call-and-response technique, which she...