At the height of the Roaring Twenties, music scouts armed with cutting-edge recording technology set out across America to capture the breadth of American music and discover the artists that would shape our world. The recordings they made of all the ethnic groups of America democratized the nation and gave a voice to everyone. It was the first time America heard itself. As told by music pioneers, their families and eyewitnesses, we travel back in time to the "Big Bang" of modern popular music with the Carter Family, Will Shade and the Memphis Jug Band.