Shape-note hymnody is the repertoire of the 18th- and 19th-century American singing schools. What strikes listeners most forcefully the first time they hear this music is its distinctive sound, standing in sharp contrast to what is heard from a choir or congregation singing traditional church hymnody. Although it has been preserved and propagated in printed form, the harmonies—often based on 4ths and 5ths rather than 3rds—and even many of the tunes themselves owe much to rural American folk music. Also, the singing-school tunesmiths sought ways for the melody to crop up in all of the voices, or at least for each vocal part to have an interesting musical line, rather than to concentrate on harmonically supporting and reinforcing a melody given to sopranos. Furthermore, men’s and women’s voices normally doubled the tenor and treble arts.
Singing schools were begun (ca. 1720s) to improve congregational singing, and their task was simplified when shapenotes were invented in 1798. Each note was given a shape that told the singer what degree of the musical scale it represented (no more learning to decode key signatures). Only four shapes were used initially, for the solmization syllables FA, SOL,A, and MI (MI is the "leading tone"). The use of shapenotes was, and is, quite effective in enabling singers to quickly sight-read and master unfamiliar music.
Shapenote music continues to be sung today by singers using tune books such as The Sacred Harp, first published in the early 19th-century and still in print. Whether sung with the surging beat and astringent vocal intonation of traditional singers, or given a softer interpretation, these songs retain the ability to move singers and listeners alike.