Oral tradition has been the basis of literature since the term came into being. Biblical stories, both Old and New Testament, were passed on for decades through campfire stories and parables before they were ever written down. Surely, one can assume, details and minutia and even entire plots and settings may have changed through the generations, but the meanings stayed strong. That is a main reason such stories are recognized with their original reverence despite an obvious factual dilemma. The purity of these stories is still present with their original spirit.
To understand literature is not simply to understand the main meaning of a story, regardless of contents. It is to understand a piece of work regardless of personal vernacular in its entirety and its original context as the author had intended. Literature must include essential subtleties that the author had deliberately placed based on his or her vernacular and the vernacular of his or her audience. Stories and music changed over generations cannot be considered literature in their original context but merely the basis thereof.
However, certain types of oral tradition, forever instilled in a place in time and location and culture through permanent manuscript or recording; forever available in the library of time and recognizable in even the most remote manner as a piece of a particular vernacular, are, indeed, literature. All forms of recorded music and written lyrics fall into this category. They can be recognized as an oral tradition’s development into something new, something different that people of all cultures, times and locations can experience and, hopefully, understand.
Oral tradition in its purest form; as field hollers and stories around a campfire, is simply not literature. They provide the basis for recorded texts and sounds that are.