OOOOOOOh.
Spirituals are so fun.
I'm sure you will be innundated with suggestions, but for your consideration, I submit:
"(Sometimes I Feel Like a) Motherless Child"
I know this one is terribly mainstream, but it's mainstream for a reason.
Here's Marian Anderson's version. She and Mahalia have been drinking the tears of envious sopranos since the 1920s or 30s. (Don't we all wish we had that BIG voice?)
..aaand
"Lonesome Valley"
Sung by the Robert Shaw chorale, in call-and-answer format.
I read somewhere that this was a White spiritual (
http://folkslingers.com/lonesome-valley/) but it's still darned good.