The claim is this: "Atnah (also called Etnahta) is the main verse divider for the twenty-one books as ole veyored is for the three. " See this article by the British and Foreign Bible Society page 12 - It is quite clear to me now that it's not all Greek.
The raw data is just too much to look at - but the claim is overstated. [stats updated - this is hard to look for accurately]
- Ole-veyored occurs in 41 of 2,525 verses by itself. It occurs with atnah in 169 other verses - and always before the atnah (that much is true).
- Atnah occurs in 2,327 of the verses.
- In some verses there are no mid verse cadences.
Ole-veyored may be a strong cadence, even stronger than atnah - that is still to be determined, but it is not main in the sense of more frequent.
BTW - Haik-Vantoura has a cadence on the supertonic for ole-veyored, but on the subdominant for atnah. These are her choices and they make good sense to a musician today.