Oh, Happy Day: What 60 Minutes has in store for Sunday The Democratic Republic of Congo is the poorest country in the world and probably the last place anyone expected to find the sweet sounds of "Oh, Happy Day," a beloved gospel hymn. But that's exactly what a 60 Minutes crew found in the heart of Central Africa for a remarkable story about the amateur musicians of the Kimbanguist Symphony Orchestra. Six days a week, dedicated musicians and singers trickle in from the slums and markets of Kinshasa to practice a repertoire of the great classical compositions, cantatas, and hymns. Many have traveled miles on foot to get there. Some arrive with their children in tow. All seem to be transported from a war-torn existence by the joys of making music. Tune in on Easter Sunday to see a story about an amateur orchestra you'll never forget. See "Joy in the Congo" on 60 Minutes (Sunday, April 8th, 7:00 PM, ET/PT) on CBS.