The tradition of hymn lining is uniquely African-American. The practice of lining hymns can be traced back to the 17th century when printed hymnals were scarce and many churchgoers—both slaves and whites—could not read. A church elder or minister who could read would “line out,” or recite a hymn line by line, which in turn was repeated by the congregation. These hymns, such as “Amazing Grace” or “What a Friend We Have in Jesus,” remained and evolved in African-American churches after the end of slavery. For Albert Troy Demps of Orlando, this tradition was passed on to him by his mother during the Great Depression, when musical instruments were scarce and times were hard. As Deacon at the Mount Pleasant Missionary Baptist Church, Demps continues to practice hymn lining, and he believes there is a more focused connection with the Holy Spirit among the congregation when the hymnal is set aside.
Floridiana Article: Troy Demps and African-American Hymn Lining