Sacred Harp singing is a tradition of sacred choral music that took root in the Southern region of the United States. It is part of the larger tradition of shape note music. Sacred Harp music is performed a capella (voice only, without instruments) and originated as Protestant Christian music. The songs sung are primarily from the book The Sacred Harp.
The name of the tradition comes from the title of the shape note book from which the music is sung, The Sacred Harp. This book exists today in various editions, discussed below.
"Shape note" music means that the notes are printed in special shapes that help the reader fluently identify them on the musical scale. There are two prevalent systems, one using four shapes, and one using seven. In the four-shape system, each of the four shapes is connected to a particular syllable: fa, sol, la, and mi; and these syllables are employed in singing the notes, just as in the more familiar system that uses do, re, mi, etc. (see solfege). The system used in the Sacred Harp is able to cover the full musical scale because each syllable-shape combination other than mi is assigned to two distinct notes of the scale.
In Sacred Harp singing, pitch is not absolute. The shapes and notes designate degrees of the scale, not particular pitches. Thus for a song in the key of C, fa designates C and F; for a song in G, fa designates G and C, and so on; hence it is called a moveable "do"system.
When Sacred Harp singers begin a song, they normally start by singing it with the appropriate syllable for each pitch, using the shapes to guide them. For those in the group not yet familiar with the song, the shapes help with the task of sight reading. The process of reading through the song with the shapes also helps fix the notes in memory. Once the shapes have been sung, the group then sings the verses of the song with their printed words.