Does the content/the gist/the details/ the theme of the story belong more to the original speaker or the re-teller? whose ideas are whose?!

With oral tradition the story is rarely written down, and I'm sure certain details get embellished, but the overall the gist stays the same.

The use of placeholders makes it a bit easier for all the subsequent re-tellers, but things are bound to change due to human forgetfulness.

Imagine trying to remember the whole Illiad! Oral tradition is a collaborative effort.