In 1953, Robert Moog
produced his own theremin design, and
the following year he published an article on the
theremin in Radio and Television News. Moog started selling theremins and
theremin kits by mail order from his home.
In 1964, Moog began creating a transistorized modular synthesizer, the first
Moog Synthesizer.
It was composed of separate modules which created and shaped sounds,
connected by patch cords.
Bob Moog - Moog company website
This instrument was made famous by Keith Emerson of the band Emersion Lake, and Palmer.
The Moog Grandmother Semi-Modular has a price of $1,250 dollars at At Sweetwater.com