Came across this in The Adventures of the Negro Cowboys by Philip Durham and Everett L. Jones, 1963. According to the authors, this book is "patterened after" their "more scholarly book The Negro Cowboys. They don't list the name of this song, nor its author, just this snippet. Maybe the first instance of black rap?*bg* Anyway, I wanted to share it with you all:

...a Negro cowboy named Add, was a range boss of the LFD outfit....According to Howard Thorp, himself a cowboy, songwriter, and ballad collector, Add was one of the best cowhands on the Pecos River.

Experience as range boss made Add an expert. He became famous among the cattlemen of the Southwest and eventually became the subject of a cowboy song. According to Howard Thorp, the song "concerns a critter found in one roundup and claimed by no one. Add was a dictionary on earmarks and brands, but this was a puzzler even to him. He read the tally of the brands:

She's got O Block an' Lightnin' Rod,
Nine Forty-Six an' A Bar Eleven,
Rafter Cross an'de double prod,
Terrapin an' Ninety-Seven;
Half Circle A an' Diamond D,
Four-Cross L an' Three PZ;
BWL, Bar XVV
Bar N Cross an' ALC.

Since none of the punchers claimed the critter, Old Add just added his own brand --`For one more brand or less won't do no harm.'

Another kind of funny story about Add. He was pretty popular and well respected. When he and his bride tied the knot, apparently "prompted by their practical wives" several ranchers wound up sending the same type of gift. Add and his bride rode up to the Roswell freight depot only "to find nineteen cookstoves waiting for them!"