In the 1950's the US Army in Germany used standard 60-cycle Hammond
organs in the chapels.  Since the organs would be low in pitch and
overheat on the 50 cycle current, a local firm had been hired to
build conversion boxes which consisted of a 50 cycle motor driving a
generator that was supposed to produce 60 cycles.  The device would
have to be switched on before the organ would run.  The result was not
exact 60 cycles, as the organs played about a semitone sharp.

I also experienced playing a Hammond organ in the little village of
Stratton, Maine in the 1960's, where the local power company's
frequency varied constantly (I assume the generators slowed down and
speeded up according to load).  Talk about wandering pitch!  Needless
to say, no one in town depended on synchronous electric clocks

The US Army's European musical inventory also included another item
extremely rare nowadays: a Steinway drop-action spinet piano.  In all
my years of tuning pianos since then, I have never seen one and
apparently no one else on the Pianotech list has, as the subject came
up recently.  I understand Steinway built a few for the WW2 troops,
otherwise building only gliders for the military during that time.

Bill Maxim
Maxim Piano Service