I happen to have a copy of the recording of Ballet Mechanique, released
around 1954(?). The liner notes indicate that it was "supervised by
the composer." Take that for what it's worth.
For all of you who have never heard this piece, I've put it up at Inlux
(yes, the whole thing, in RealAudio). The fidelity doesn't suffer much
from the translation into RA, and most, if not all, of the original
comes through. It's a pretty clean LP considering the age (and abuse)
so I didn't go through the hassle of de-clicking it. It's one of my
favorite pieces, incidentally. Look for the flashing "new" button at
the top of the left side bar.