There's a 4 part documentary about Alexander Courage, best known as the guy who composed the original STAR TREK theme, over at YouTube. It's hosted by John Williams, and put together by Malibu Films. I stumbled on it today and know little about the production, except that it's to commemorate the first "Courage Awards."
It's fun thinking that for a while in the 1960s, "Johnny" Williams' music could be heard on CBS' LOST IN SPACE and Courage's on STAR TREK on NBC. (And, well, to make it more true and more muddy, now that I think of it, Courage did work on LOST IN SPACE as well.)
Here are links to part one, part two, part three and part four. The 4th part is about his TV music. He confesses he's not a science fiction fan, and thinks of SF as "marvelous malarky," so he wrote what he calls a "marvelous malarky" tune. And wait til you hear how they did the "whoosh" sound of the Enterprise in the opening credits!
There is even more here -- a couple hours that I haven't seen yet. It's an interview for the Archive of American Television.
(The Archive of American Television has a ton more here. You can see other Trek composers chat about their careers, and Nimoy and Shatner and others are there too. These are multi-hour, life-spanning chats, and I have seen only a few of them. Go wade in.)