Allyn,
I may be inventing memories, but I distinctly recall that the Smithsonian
(or maybe LC) used to issue records containing "classic" music that was
public domain.  None of it may be early enough for you, of course, but
OTOH it may be better than nothing.  Since David didn't mention these
recordings, maybe I am making it up.  Anyway, good luck.

Michaele & David    [log in to unmask]