Sophie Tucker (1887-1966), the legendary "Last of the Red Hot Mamas," was a Ukrainian born but thoroughly Americanized jazz singer, who belted out songs with the style and personality of Ethel Merman and Bette Midler, who were among the many performers who were influenced by her. Although she did make movies, she was primarily a vaudeville and nightclub singer until her 1965 retirement. She recorded her signature song "Some of These Days" for the first time in 1911, and it was an immediate hit. Portrayed by Kathy Brier, Tucker appears in the nightclub scene in which Nucky proposes the mayor's job to Edward Bader.
Mary Cassatt, whose work is compared to Angela's was an American painter and feminist, who spent most of her life in France. Her subject matter was portraits of women or mothers with their children. She found acceptance by the art establishment difficult but was embraced by the Impressionists, especially Degas, with whom she was very close. Unlike Angela's work, Cassatt did not paint nudes.
The episode title, "Belle Femme," is the name of Madame Jeunet's dress shop.