http://www.youtube.com/watch?v=DXJJ2Ek4bmQ
The Vako Orchestron is an old-school style optical competitor to the Mellotron.
The Orchestron, which was adapted from the Mattel Optigan, was introduced in 1975 by Dave Van Koevering. It was intended to be a competitor to the Mellotron, but it never really took off.
More information about the Orchestron and related instruments is available at the Optigan site.
I was a customer and frequent visitor of Dave V’s music store on Central Ave in St. Pete FL during the period that the Orchestron was being developed. I recall the day that Dave showed me and a few others the Optigan that he had gotten from some sales rep. It was just a toy but we all thought that it was cool. Everyone had their eye on a mellotron of course but this held promise for something similar in a bit more portable form.
Just thought and acdote from that time period might be of interest.
Ray Eales