What is shape-note singing?

Perhaps the best place to start looking is the Sacred Harp Musical Heritage Association web page. 

Jack Puskar (who sings great tenor with us) made this table of the 25 most-often sung pieces from the Sacred Harp.

There's a wonderful article here by Laurie Kay Sommers about the Hoboken GA Sacred Harp singers, including some audio and video.

Photos

Singing in the Evangelical Lutheran Church in Worthington PA:

After singing in the tent in Schenley Plaza (thanks to Donna Isaac of Calliope for organizing!). Thanks to Jo Schlesinger for the photo! See here for more pictures.

Shape note factlets

Shape note singing is a descendant of the usually unaccompanied harmony singing practiced in 18th-century New England churches. Before that time, the congregations sang hymns and metrical psalms in unison using a lining-out procedure: the deacon (or minister) would read the verse, then the deacon "set" a line by singing it to the psalm tune, and the congregation in response sang the same thing (in theory!), and the setting and singing proceeded line by line. No organs or other instruments, not even a pitch-pipe, were allowed in the New England churches, so the poor deacon had quite a job, as everyone who has "pitched" for shape-note singing knows (but the deacon was responsible not only for the pitch, but for knowing the tune and leading it). Here's a bit from the diary of Samuel Sewell, deacon for Boston's South Meeting House:

Dec. 28, 1705. ... Mr Willard preaches from Ps. 66.20 very excellently. Spake to me to set the Tune; I intended Windsor, and fell into High Dutch; and then, essaying to set another Tune went into a Key much too high. So I prayed Mr White to set it; which he did well, Litchf. Tune. The Lord humble me and instruct me, that I should be the occasion of any interruption in the Worship of God.

[Source: Alan Clark Buechner. Yankee Singing Schools and the Golden Age of Choral Music in New England, 1760–1800.]

Here's an interesting short piece by the writer Charles Fergus on Ananias Davisson, author of Idumea, and his book The Kentucky Harmony, which was so important in spreading shape note music as the frontiers expanded.

In Melville's Moby Dick (chapter 22), when the Pequod sets sail from Nantucket on an icy Christmas evening, Captain Bildad, the pious Quaker who owns part of the ship, pilots her out of the harbor. The narrator describes the scene as follows: 

As the old Craft deep dived into the green seas, and sent the shivering frost all over her, and the winds howled, and the cordage rang, Bildad's steady notes were heard.

"Sweet fields beyond the swelling flood,

Stand dressed in living green.

So to the Jews old Canaan stood,

While Jordan rolled between."

Never did those sweet words sound more sweetly to me than then. 

[Bildad was singing Jordan (first) by Billings. Source: The Core Repertory of Early American Psalmody]

At the Augusta Heritage Festival 2015, Dr. Ron Pen of the University of Kentucky did a presentation in honor of Jean Ritchie (who died the previous spring). It seems the Ritchie family's custom was to get up before dawn on Christmas morning and go out singing carols. One of the songs they sang on these occasions was Wondrous Love. I had the privilege of participating in the singing of this hymn for Ron's presentation.

Videos from the Pittsburgh Regional All-Day Singing: Saturday March 22 2014

Thanks to Michael Kearney!