Nineteenth century American song books that used notes in different shapes to aid singers and teach singing came to be known as “shape-note hymnals” and the style of singing from these “shape-note singing.” Christian hymnals using this system were among the most enduring uses of this notation. Among the most popular was The Sacred Harp by B. F. White, first published in Georgia in 1844. As a result of this popularity, the style of singing is also sometimes called “sacred harp.”
Below, same song, from a group in Ireland.

I haz lernd today.