Roger and Allison Kulp wrote:

> There are actually some decent recordings done binaurally 
> by RCA as far back as the mid to late 30s,
> where the left and right channels were recorded on separate discs,
> and played back on tandem turntables.
> The Ellington recordings were eventually released on a CD,in the 
> 90s,or early 00's.Was Blumlein's work independent of this?


The RCA recordings to which you refer were accidents. RCA was trying to 
develop its own electrical recording process, so it could supplant the 
Western Electric system and its enormous licensing fees.

In order to gauge the progress of their research and experiments, RCA 
had to occasionally bring their equipment into the studio, where it 
would be set up in a completely different chain from microphone to 
cutter, alongside the WE equipment.

These recordings of the same sessions would then be auditioned back to 
back; the engineers knew the strengths and weaknesses of the WE system 
and could judge where they needed to improve their RCA system. That the 
RCA system wasn't considered "ready" at the time of the 1932 Ellington 
sessions is shown by the fact that it wasn't used commercially until 1934.

As tempting as it may be to think that this was a grand experiment in 
stereo recording, keep in mind that it is well-nigh impossible to 
maintain synchronization between two different turntables NOW, with all 
our modern advances. Think how impossible it would have been with the 
more primitive 33 1/3 RPM equipment of nearly 80 years ago.

(I recall reading somewhere that Seth Winner and Steven Lasker did a lot 
of on-the-fly manual pitch adjusting between the two turntables being 
played simultaneously, to try to keep the two sets of accidental stereo 
records synched. And the Winner studio has far, far better gear than 
they had back then.)