In Sept 2006 a Guest posted this link to the 1980 WireGrass Sacred Harp Singers in Mudcat's Alabama Slave Spiritual Music thread.

I'd never heard of this type of singing before. Nor had I ever heard of the song "Pisgah" [a audio clip is provided for this song]

Here's excerpt of the end of article notes about the song "Pisgah":

"Dr. Warren Steel writes of "Pisgah":
"Both George Pullen Jackson and Dorothy Horn in Sing to Me of Heaven called this and other tunes folk-tunes even where no secular sources could be found, based on rather inconsistent musical characteristics1; but there are good reasons to suppose that the tune for "Pisgah" may have been in the oral tradition--whether secular or merely camp-meeting religious none can tell. But the same tune was published in a different setting, with a different title, by Alexander Johnson in 1818. Johnson lived in Maury County, Tennessee. His treble has been inserted into the James/Denson/1991 Sacred Harp as the alto part of "Pisgah." The first printing of the tune "Pisgah" is in Kentucky Harmony, 2d ed., 1817, attributed to J.C. Lowry.

"Note by Peter Ellertsen:
Jackson says Pisgah is of English origin and may be related to the ballad "Little Musgrave and Lady Barnard" (Spiritual Folk-Songs 144). Song collector Annabel Buchanan notes its resemblance, in some variants, to the old ballad and says she heard her parents and grandparents sing the text, "When I can read my title clear" to Pisgah when she was a child (Buchanan xxxi-xxi, 84). After reviewing the evidence available on its antecedents, Horn says its British folk origins are "certainly open to doubt." She concludes, "Perhaps someone else can determine the amount and direction of lend-lease involved here" (34-35). Whatever its origins, it was in Missouri Harmony and appears to have been a favorite in the early 1800s. "Pisgah" was first published in 1817, the 2nd edition of Kentucky Harmony."

Karen Willard notes:
George Pullen Jackson's in White Spirituals in the Southern Uplands (1933, page 47) says "Pisgah" is one of the eighty most popular tunes he found in the southern shapenote books. George Pullen Jackson in Spiritual Folk-Songs of Early America (1937, page 123) says it is in the Methodist Hymn Book of England labeled an American Melody and titled "Covenanters." Ellen Jane Lorenz Porter in A Treasure of Campmeeting Spirituals (1978 diss, page 159) calls "Pisgah" a campmeeting hymn and suspects it's based on a secular dance tune."