In the small towns and rural areas of early America, church-sponsored "singing schools" proliferated as a way of both improving congregational singing and drawing communities together. Congregants attending these schools were taught a form of musical notation in which the notes were assigned different shapes to indicate variations in pitch--a method that worked well with singers having little understanding of standard musical notation. These schools eventually became major social events that drew hundreds of attendees, and today countless enthusiasts carry on the shape-note tradition.

The...