"Shaped Note Singing" or "Sacred Harp Singing" is considered a
folk art form from the Southern U.S. in the 1800s. The songs are
hymns from editions of the Scared Harp song and are sung loudly
and without accompaniment. Before the first verse, tradition
requires that the notes be sung with the Fa, Sol, La and Mi note
names instead of words. The music notation in the song books
uses different different notes. Fa is a triangle(flag), Sol is a
La is a square(2 Ls make a square) and Mi is a diamond (diamonds
for me).