I suppose it depends on who they get to make the film. I can't imagine Betty Boop without jazz music. I think it was mostly of the Dixieland variety. Pre Thelonious Monk.
You can count on American films, even the really stupid ones, to be technically excellent: you can hear the actors clearly and distinguish between them, unlike films made in earlier times.
I highly recommend the film "Belle" which recently became available for rental from Amazon.
A really good period piece, based on a portrait in a British mansion and little else. The action takes place in the late 1700's, and there is no mention of the American revolution at all. The subplot is about an insurance claim of a British company that overcrowded a slave ship called the Zong. The ship had somehow been highjacked by the British from a Dutch slaver captain, hence the strange name. Actually, the ship was named the Zorg, which means "Care" in Dutch. Some of the slaves were ill, and the captain ordered them to be thrown overboard, chained together, so the company could be recompensed by the insurance company as damaged merchandise. The main part of the plot is the courtship and marriage of Dido Belle Lindsey, the mulatto daughter of a deceased British sea captain of noble birth.
I suppose the only historical anomaly would be what no one really wants to see: tons of horse dung in the streets of London and everywhere else.
Years ago, my father and I went up Pikes Peak on burros. It was a two day trip that took about 12 hours on horseback, through a very scary place where years before gnarled old pines had been burnt in a forest fire and somehow had not grown back. Perhaps because it took centuries for them to grow in the first place. It was called the Dismal Forest.
One thing I noticed was the huge amount of burro crap, mule poo and horse road apples all along the trail. There was only about three trips up the mountain per week, but there was six inches of the stuff and you could see very clearly where the trail went as it wound through the trees, that looked like the scary forest in a Disney film.
