Didn't the Siddur come after the Torah Scroll? Didn't TaNaK come after Torah Scroll? Didn't the Talmud come after the destruction in 70CE? There is a relationship between the Siddur and Talmud. So might not this be evidence that this is a true part of the Sefer Torah. I remember Rabbi David Stern so many years ago, on a magical Saturday pre-service said these very comforting words at Temple Emanu-El Dallas TX. I hold on to these words because it gave me confidence in me. To the effect: after all is said and done Judaism is the Sefer Torah and the rest is the application of the Sefer Torah.
I don't understand how Judaism could have survived if there hadn't been a Sefer Torah in existence.
What I like about it is this: The Trope Trainer is the e-Sefer Torah. Every single character and space has been statistically verified for how long? It was sung because that's the best way to transmit information orally sturdily. In fact, it's only been in the past ten years that we now apply Western Musical Notation. When I bat mitzvahed, I had to learn listening to the tapes of the Cantor, in 1981.
Ancient Torah texts on display - Israel Culture, Ynetnews