"A song in the affirmative"

Here is what Gerard Vanderleun writes about this song at American Digest:

Yes, this was sung and filmed within living memory. Seen now its textures, singers, tones, hues and the spirit of a confident culture give it a luminosity that cannot be recaptured no matter our wealth and technical capability. Yet it still has the capacity to soothe and comfort and uplift. It's a song in the affirmative. It would be nice to write and sing songs in that key again.