On Wed, 1 Jan 1997, Dave Schutt wrote:
 
> I saw one of these about 1950. I don't know if they were ever sold
> commercially by Baldwin. My recollection is that they had the sounds
> recorded on photographic film. Seems like the mechanism had lots of
> mechanical noise.
> --
> Dave Schutt <[log in to unmask]> San Jose, CA
>
 
If I remember right the optical organs made in the '50s were made by
Kimbal but there may have been some other makes/models I have not seen.
 
Electrovoice had an interesting disk tone generator that worked on a
capacitenece electrostatic principle. I have one of these tone generators
and the recordings are very real sounding but with one major problem. The
realism in sound is only good within the middle octaves and degrade
somewhat as you play scales down or up. They used the same identical wave
patterns for twelve notes and just vary the rotation speed accordingly.
 
Gary K.