The Sorcerer of the Wildeeps by Kai Ashante Wilson

Since leaving his homeland, the earthbound demigod Demane has been labeled a sorcerer. With his ancestors' artifacts in hand, the Sorcerer follows the Captain, a beautiful man with song for a voice and hair that drinks the sunlight.

The two of them are the descendants of the gods who abandoned the Earth for Heaven, and they will need all the gifts those divine ancestors left to them to keep their caravan brothers alive.

The one safe road between the northern oasis and southern kingdom is stalked by a necromantic terror. Demane may have to master his wild powers and trade humanity for godhood if he is to keep his brothers and his beloved captain alive.

"Wilson isn't the first black writer to demonstrate the possibilities of mixing traditional fantasy tropes with African-American culture, of course, but few have concentrated so brilliantly on the linguistic implications of doing so." --Strange Horizons