[78-L] Roots of Rock n Roll (was: Back Beat Boogie)

[agp]

Admittedly, I don't know much about this sort of stuff, and the topic 
is very much open to, no doubt, loud and argumentative, debate, but 
-- what floored me about Back Beat Boogie by Harry James was a sound 
that was so very much like 50s rock'n'roll, that anyone could pick it 
out,if not mistake it for a 50s recording.

Am I correct in saying that the back beat is what is makes it so?

What other early 40s, 1930s, and before (is that possible?) tracks 
have that direct to rock'n'roll sound.

Although thought of by some, Rock and Roll by the Boswell Sisters 
merley uses the term. Rock me by Sister Rosetta Tharpe seems to be 
there. Caldonia by Louis Jordan is there..

Just wonder what others qualify

T