Roger Hecht:

>Steve Schwartz wrote:
>
>>Marius Constant.  The theme was, I think, for Twilight Zone (or was
>>that Bernie Herrmann?).
>
>Twilight Zone was Herrmann, I'm pretty sure.

Constant wrote the main theme.  Herrmann wrote for a number of episodes.
Others who composed for the series included Jerry Goldsmith, Max Steiner,
Franz Waxman and Leith Stevens.  I remember Stevens best for his music
for The Wild One which I once owned on a 10" LP (yes, there were such
things).

Richard Pennycuick