While living at MSP, many African-American inmates sang work chants, a tradition traced to West Africa. Work chants were used by farm laborers to pace their work. While inmates worked, a leader called the chant, with other inmates following him. One song includes a story of an inmate swimming through the Sunflower River to confuse bloodhounds, verses showcasing prisoners who return hoes to their commanding captain and refuse to continue working, and a story of a beautiful woman named Rosie who waits outside the prison boundary. William Ferris, author of "Give My Poor Heart Ease", said that "for all of these inmates, music was a means to survive within the prison's grim world." The Mississippi Blues Trail added Parchman to its list of sites at 10 AM on Tuesday September 28, 2010; Parchman received the trail's 113th historical marker.