From Richard Crawford, America’s Musical Life: A History, Norton 2001, p. 156:
In 1933, George Pullen Jackson . . . published a book – White Spirituals in the Southern Uplands – about a remarkable tradition he had encountered among “plain folk” in the region. From the time he settled in Nashville in 1918, Jackson noticed a practice of sacred singing that was being carried on outside the churches. Gathering on weekends, groups of Southerners staged all-day “singings,” and they brought their own books: thick, oblong volumes of psalm and hymn tunes, and anthems set mostly for four-part chorus with the melody in the tenor voice. They seated themselves according to voice part . . . in a rectangle with an open space in the middle. Into that space stepped a succession of singers from the ranks, each leading the group in two or three pieces. . . . The sound of the singing . . . took some getting used to. The singers tended to vocalize full blast at all times, making no attempt to blend.
Crawford then goes on to quote from Jackson’s book where he describes a reception that followed a singing contest for children:
At first the happy children received merely a warm hand-shake and pat on the shoulder from the men and a kiss from the women. But by degrees the wave of emotion rose, swept on by this song and then by another one spliced on, and by the really parental joy in those children who had so beautifully proved that they could carry on their fathers’ and mothers’ beloved art – until the warm congratulatory reception became a veritable and ardent “love feast.” The little ones were smothered with kisses and hugs. Tears streamed down the cheeks of young and old. And one particular fat man, looking on, crying, laughing, seating, and fanning, shouted intermittently.