Rags-to-riches entrepreneur Madam C.J. Walker and her daughter, A’Lelia Walker, built one of the most successful African American hair care businesses in American history. But it was only after A’Lelia broke free of her mother’s singular vision that she found her calling in 1920s Harlem. That search for independence and purpose is at the center of A’Lelia Bundles’ new book, “Joy Goddess: A’Lelia Walker and the Harlem Renaissance.” It’s our May selection for Bookmarked: the “Under the Radar” book club.