Book excerpt: Tracing the relationship of black sacred music and social change, Wyatt Walker observes, ". . .if you listen to what black people are singing religiously, it will provide a clue as to what is happening to them sociologically." Walker traces the musical expressions of the black religious tradition from its roots in the "invisible church" of the slave society to its influence upon the black religious experience today. He challenges the black church to preserve this rich musical resource so that black sacred music will become one of the gifts of black people to the church universal [Publisher description]