I am always amazed, in those scenes in which the stars spontaneously burst into song, at how quickly the bystanders learn the lyrics and even sing heretofore unheard verses! Add to that the unlikelihood that bystanders would even bother to sing at all in real life. God knows how difficult it is to get an audience to sing along when you want them to.

Five-string banjos appear in many portrayals of historic scenes long before they were created.

Automobiles, telephone lines, jet trails and even mountainside firecuts (those clearcut lanes that help to prevent the spread of forest fires,) all appear as anachronisms in the backgrounds of many movies.

And when is Hollywood going to catch on that the Old West was not all White and in fact had a HUGE Black population of cowboys, etc.? (This is most certainly a rhetorical question - I know the answer!)