[ Rich Marschner wrote: ]

> Throughout the film, beginning with the opening credits and running
> right on through the closing ones, the soundtrack is layered with
> Theremin effects and some music, very much helping define the eerie
> atmosphere of the forbidden planet itself ...

In fact this music did not originate from a Theremin, it was electron-
ically "realized" from custom-built instruments designed by Louis and
Bebe Barron.

Forbidden Planet was the first film to use a music track that was
totally synthesized electronically, and the impact of the Barrons' work
on the film was extraordinary.  High-concept movie, highly recommended.

A. B. Bonds