which might or might not be a separate unit from the keyboard.

Funny that you mention it. Synthesizers are very much a product of university research programs. Back in the 60’s and 70’s, when synthesizers as a concept was still new, there was heated debate between the pioneers of the field (Robert Moog in New York and Donald Buchla in Berkley, California) over whether or not synthesizers should even have.

The origin of the word “synthesizer” isn’t actually “synthetic”, as many believe, but rather synthesis, as in the academic sense of the word, from the idea of breaking a sound down into it’s individual parts and reassembling them.