The data integrity operates on the level of story line and major themes. Formulae are at the word and phrase level. If the written is subordinate to the orally

The data integrity operates on the level of story line and major themes. Formulae are at the word and phrase level. If the written is subordinate to the orally extemporaneous, like jazz, maybe you memorize a few star solos, but memorization isn't how you play a solo as a jazz musician. It's like asking "Did Hansel and Gretel see Rapunzel along the way?", and the answer depends on whether a book or a culture creates the stories their use. If you have no writing, all of your community's texts are fan fiction with limit on headcanon. People brought tape recorders to Bosnia in the 1930s, to try to see how oral folk music worked, and to see how much it changed day to day and year to year, and they found that they couldn't glue the same story together from day to day.