In Chapter 2 of Jonah's Gourd Vine, Charlie describes Lucy Potts singing at church: "...she trebles right 'long wid dem grown women and kin sing all de notes--de square ones, de round ones, de triangles."
What may sound like a flowery way of describing music is actually referring to a specific type of singing and musical notation: Sacred Harp singing, also called shape-note singing, a style that gained popularity in the 1800s in the South. Unlike the eight-note "do-re-mi" style we all learned from The Sound of Music, Sacred Harp singing uses an older four-note English system, with different tones given different shapes in the songbooks:
Sacred Harp singing has a couple of other distinctive qualities, which are much more noticeable when you experience it live: first, the singers sit facing each other in a hollow square, with each side representing a specific vocal range (treble, alto, tenor, and bass); and second, it's loud. Really loud. Sacred Harp singing has no volume indicators that occur in more modern music, so singers tend to just belt it out. Watch the video below for an example of modern Sacred Harp singers:
Interested in checking out Sacred Harp singing in person? The St. Louis Shape Note Singers meet several times a month, often in a home in University City. Check out their website at http://www.stlfasola.org/ and remember to sing loud!