(3-CD set) The first half of the 20th century, vocal group singing was one of the most progressive and inventive of African American arts. In the absence of instruments, singers had to work much harder to make sure that their own distinctive sound grabbed and held the attention of the audiences and record buyers. The leaders in the field were groups like the Soul Stirrers, the Flying Clouds of Detroit, the Southern Sons, the Pilgrim Travelers, and the Wings Over Jordan. Some of their rarest recordings are included in the 3-CD box set. Notes by Ray Templeton.