Who was first is filled with conflicting information.  However, let the
record show that at least some initial stereo recordings were done by Bell
Laboratories in conjunction with the Philadelphia Orchestra conduced by
Leopold Stokowsky in approximatly 1927.  This purely research effort was
done under Bell Labs development activity directed to motion picture sound
technology from which most of todays modern microphone and loudspeaker
technology evolved on the American side of the Atlantic.  With no magnetic
recording technology available the recordings were done direct to disk as
was the universal industry custom before the late 40s.  The experimental
recordings were created using both 45/45 disc cutters predating the
standard of popular stereodisks introduced in the late 50s and also
horizontal /vertical disk cutting.  I believe there was a stereo LP record
with numerous musical examples made in small quantities to commemorate the
efforts of this pioneering group of Bell Labs/Western Electric researchers,
now mostly deceased.  This record was available at least through the early
80s but, a current source of copies is unknown to me.  I also believe that
one or two members of the Boston Audio Society, who were retired AT&T
employees, had access to these documentary recordings in the 80s time
period.  Persons interested in tracing the history might inquire at both
the Society Of Motion Picture and Televison Engineers headquarters and at
the Audio Engineering Society web site in New york City.

Bernard Gregoire
Hingham, MA