Here's a rather wonderful 1947 short from the Internet Archive about the place of the banjo in American folk music. Its written by the great folklorist Alan Lomax and narrated by Pete Seeger who guides us through a series of loving portraits of country folk and their musical traditions. Along the way, we learn that the banjo was invented by slaves, that Appalachian ballads have their roots in Scottish folk songs, and that exchanges across the racial divide have long played a significant role in the formation of American folk music. The whole thing ends with the off-screen audience of proto-teeny boppers taking to the stage for a lively square dance. (via Indestructible)