I have watched this a few times since the first buzz a month or so ago. Very informative and entertaining... but it is the sound that has been echoing in my mind these last few weeks. After thinking about it, (or rather, clearing my mind and letting the associations create themselves) I am almost certain that the musical soundtrack may have been composed by Raymond Leppard, the British conductor and film composer. Of course, it could just be a product of its time, but the music is very similar to his soundtrack for Lord of the Flies, from the same era.
... just a little bit of trivia of absolutely no consequence...
By the way, I met Mr. Leppard in the late '70s while studying for my music degree in Windsor, ON. Charming fellow (who cussed like a trucker... )