Nigerian literature has a long history in the oral tradition. Bade Ajuwon's article, "Oral and Written Literature in Nigeria," found in Nigerian History and Culture, explains:
Pre-literate Nigeria once enjoyed a verbal art civilization which, at its high point, was warmly patronized by traditional rulers and the general public. At a period when writing was unknown, the oral medium served the people as a bank for the preservation of their ancient experiences and beliefs. Much of the evidence that related to the past of Nigeria, therefore, could be found in oral traditions.
Although most Nigerians knew and could recount parts of their genealogy and local history, only a few oral artists had the skill and stamina required to chant the lengthy oral literature. The oral artists, freelancers or guild-associates, enjoyed reverence as "keepers of the people's ancient wisdoms and beliefs." These oral artists frequently entertained their audiences dramatically, providing relaxation and teaching moral lessons. In Yorubaland, "as a means of relaxation, farmers gather their children and sit under the moon for tale-telling. . . .The telling of stories is used by narrators to instruct the young and teach them to respect the dictates of their custom: as a result, a large body of moral instruction, of societal values and norms are preserved for posterity by the Yoruba."
From: Bade Ajuwon, "Oral and Written literature in Nigeria," Nigerian History and Culture, Richard Olaniyan, editor. (Hong Kong: Longman Group Ltd, 1985), pp.306-318, 326