[Video Link] "Oh Mary don't you weep," an early film recording of unknown origin, found on YouTube with the description "Georgia Field Hands, recorded 1928-1935." More about the song, which was a sort of coded message of resistance in the American South, and seems timely today, with current events in Egypt. Thanks to NPR's Andy Carvin for the inspiration.
Lyrics here.
There have been many great renditions of this song throughout the ages; Aretha Franklin's from 1972 is one of the finest to be found on YouTube.