About "Song of the Creation," it seems to have been Gilkyson's take on a piece of the old song "Walky in the Parlor," an early version of which is cited (to a very different tune) by Dorothy Scarborough, On the Trail of Negro Folk-Songs, p. 181-2 (excuse the language, please):

STORY OF CREATION

First he made a sun, then he made a moon,
Then he made a possum, then he made a coon.

All de other creatures, he made 'em one by one,
Stuck 'em on the fence to dry as soon as they was done.

Cho: Walkee-in, walkee-in, walk in, I say,
         Walk into de parlor and hear de banjo play,
         Walk into de parlor and hear de niggers sing,
         And watch de nigger's fingers as he picks upon the string,
             Zing, zing, zing, zing; zing, zing, zing.

Old Mudder Eve couldn't sleep widout a pillow,
And de greatest man dat ever lived was Jack de Giant-Killer.   

[further verses have no Eden content]