The evolution of social change in America can be traced through popular songs by the likes of Nat King Cole, Percy Mayfield, Lena Horne, and the Impressions. Charlie McGovern shares from his book Body and Soul: Race, Citizenship and Popular Music, 1930-1977. Also: Music streaming platforms like Spotify and YouTube have changed the conversation about music and democracy. These days we talk about individual freedoms to choose what to listen to and when. Nancy Hanrahan says debates about music and democracy used to focus on a shared national identity, morality, and citizenship.

Later in the show: Noel Lobley wanted to give colonial musical archives back to the people--so he strapped DJ booths to donkey carts and took to the streets. Plus: Since long before Louis Armstrong was sent to Egypt as a representative of the State Department, the United States has been using music as a key part of diplomacy. Arthur Romano, a consultant on State Department musical missions overseas, says music is an important form of conflict resolution.