Overview:Former slaves spread the gospel of African-American music in an inspiring 2000 chronicle of the 1870s Tennessee vocal group Jubilee Singers that introduced such songs as "Swing Low, Sweet Chariot" and "This Little Light of Mine" into popular culture. Dion Graham narrates the hour, which follows the Jubilees as they tour the U.S. and Europe. They had to battle racism and internal strife, and in the process saved their school -- Nashville's Fisk University -- from bankruptcy. More important, they permanently broadened American music.