There's a YouTube video of Dark Was the Night, Cold Was the Ground.
I found a some interesting quotes about the song:
Ry Cooder has infamously termed this song "the most soulful, transcendent piece of American music recorded in the 20th Century," and it's hard to argue. "Dark" is an unspeakably mournful evocation of an 18th century hymn that includes the preacher's singing followed by the congregation answering in song, as replicated on an acoustic slide guitar.
emusic Magazine
Possibly his most well-known piece today is the free-form guitar impersonation of a congregation moaning "Dark Was The Night And Cold The Ground", which was used in its original form in Pasolini's film The Gospel According To Saint Matthew and adapted by Ry Cooder as the theme music to Paris, Texas.
Source: Encyclopedia of Popular Music, quoted at www.authentichistory.com
In Lawrence Cohn's book "Nothing but the Blues", one can find a rather unlikely history of the composition and later arrangement of this song. In Cohn's book, there is a section called "The Gospel Tradition" that was researched and written by Mark A. Humphrey. Thomas Haweis was an English physician and clergyman who wrote this song and hundreds of other hymns. Its original title was "Gethsemane" and was published in a book of hymns dated 1792. It is among the many hymns that were taught to American Negro slaves in the 1800's by British missionaries.
http://www.hlmusic.com/darkwas.htm
I think this may be the original song:http://www.cptryon.org/xpipassio/hymns/dark.html
Dark Was the Night
1.
Dark was the night, and cold the ground
On which the Lord was laid;
His sweat like drops of blood ran down;
In agony he prayed.2.
"Father, remove this bitter cup,
If such Thy sacred will;
If not, content to drink it up
Thy pleasure I fulfill."3.
Go to the garden, sinner, see
Those precious drops that flow;
The heavy load He bore for thee;
For thee he lies so low.4.
Then learn of Him the cross to bear;
Thy Father's will obey;
And when temptations press thee near,
Awake to watch and pray.
The tune is Richmond (click), which doesn't sound like the Blind Willie Johnson song to me - but I have a hard time tying moans to their original songs.
-Joe-
There's an extensive study of the song at http://www.metafilter.com/45137/Dark-Was-The-NightCold-Was-The-Ground-by-Blind-Willie-Johnson.
Oh, and take a listen to this YouTube Recording by the Kronos Quartet.
Also take a look at American Negro Folk Songs, page 105.
You'll hear two samples of other singers singing this song on a Folkways recording here (click)
-Joe-