All across the country, but especially in the South, people will gather weekly or monthly to sing "sacred harp" songs. These songs are a capella, four-part harmony, using "shape notes" rather than modern transcription, and are a living tradition going back to the early years of our nation.

Here is the official website of the Sacred Harp Heritage Association, that has description, history, and other information, including locations of "singings" that anyone can participate in.

Some examples of Sacred Harp singing:

What Wondrous Love Is This, from a singing in Columbia, Missouri. Sound quality if amateur, but a good introduction. Notice that the singers begin by going through the tune fa so la, etc. Sacred Harp schools were held on the frontier in the 19th century and within a week could produce high quality choral singing from whatever group of pioneers were gathered. Rather than being taught conventionallly, the men and women were taught to associate notes with pitch using the do, ra, mi, etc

From Birmingham, Alabama.

This is an "internet ad" promoting a singing in Newbury, Vermont.

From the Cold Mountain movie soundtrack, better sound quality obviously.