Allmusic.com attributes RED SUN to Langston Hughes and Josh White. I'm guessing that means it was originally a poem by Langston Hughes, and Josh White later set it to music. I suppose it's also possible that they collaborated. This discography says Langston Hughes wrote the liner notes to one of Josh White's albums—but that was in 1944, and RED SUN didn't appear until 1960.

Anyway, here's an excerpt. It's the best I can do for now. I would recommend looking in a book of Langston Hughes' poetry.

Red sun, red sun, why don't you rise today?
Red sun, O sun, Why don't you rise today?
Ma heart is breakin'—my baby's gone away.

Little birds, little birds, ain't you gonna sing this morn?
Says, little chirpin' birds, ain't you gonna sing this morn?
I cannot sleep—ma lovin' man is gone.