"Griots And The Oral Tradition
The blues follow the west African tradition of the "griots." The griots were the libraries of their tribe. They held the history and the culture of their tribe, often in songs, and passed that knowledge on to their descendants.
The African-American songsters who synthesized the blues from earlier genres of black folk music were descendants of the griots, carrying forward the historical and cultural legacy of their people even while they were setting a new agenda for political discourse and action.
These new griots helped to continue the oral tradition. Through their songs, they often expressed discontent with their situation and their hope for change."

Maybe I'm opening up a can of worms. How strong is the case for griots having anything much to do with the blues? As far as I can tell, every culture, every group even, has some guy who's a 'library', often in song. It seems a bit like saying that medieval Andalusian oud players are fathers of the blues.