Here is a lossy version of one of the Ellington recordings:
https://www.youtube.com/watch?v=wGt9uXmTd8A

Why does the phase seem to waver? Is it timing errors between the disk playbacks?

Here is another one from the Victor vaults:
https://www.youtube.com/watch?v=u5AIkD5CtUs

I can't tell if this is really two different mic perspectives or different recording and/or playback
EQ. It seems like the right-hand disk is louder overall. However, some of the background instruments
seem to arrive at different times in the two channels, indicating separate mics in different
locations.

As far as "Sacre" performances go, this one is taken a good bit slow for my taste.

-- Tom Fine