I am reading on Wikipedia about how the Rig Veda was orally passed down "with unparalleled precision". And how it is divided into 10 books, with books 2-7 being the "family" books which are older and go together more than books 1, 8, 9 and 10. But what is missing from this picture is how the oral form organized the information. Did they organize it into these 10 mandalas? Or was it just a bunch of hymns that were memorized.
It is said that it wasn't written down until maybe roughly 1000CE, while it was probably orally transmitted for thousands of years before that with high precision. What sort of way did they orally organize the information? Did they organize it into mental "books"? Or is the whole idea of 10 books an entirely new phenomenon?