Hi Jody,  The 16-2/3 rpm speed was used on a limited basis but
recordings were available to play high-fidelity stereo music.

A friend of mine, Hugh Burdick, made some of them well over thirty
years ago.  In fact, he made a set of them especially for funeral
homes.  They could play up to one full hour on each side.  There were
recordings for Catholic services, Protestant services, and I believe
the other of that series was for Jewish services.

He also produced another recording of popular music that also was
recorded in high-fidelity stereo.  I still have a copy of that one
around here somewhere.  Just a bit of trivia, Hugh mastered these
recordings on a very fine Crown reel-to-reel recorder that I'd have
liked to have for my own.  This is the Crown that was made in Indiana,
not the Japanese one.

Recordings made for sending messages overseas during WW2 were at
78 rpm, at least all of them that I ever saw.  In 1940 we bought a
Silvertone radio-phono-recorder combination that was in a table top
cabinet.  On several occasions we received voice messages from friends
overseas during the war and were able to play them and make other
recordings in response on our Silvertone.

The recording booths were often found in areas of high traffic so that
anyone could step in the booth and make a recording, typically of one
or two minutes in length.  Of course, they required coins to be
inserted.

Hal Davis