What can one Broadway tune reveal about the history of American race relations? In his book "Who Should Sing Ol' Man River?: The Lives of an American Song," musicologist Todd Decker explores how the meaning of "Ol' Man River" has been reshaped over time. Discover the song's surprising journey from Broadway ballad to pop anthem, dance ditty, activist anthem, and beyond. (A version of this episode was first released in 2013.)