The use of "thou" after the Early Modern English Period
In the introduction there are already some hints to possible uses of "thou" which go beyond the Early Modern English period or even belong to the present day: language used in church, Metallica Songs or Star Wars.
After having dealt with the use of "thou" and "you" in different contexts in Early Modern English, we have a good basis to take a look at the last two examples from a different point of view:
In the Star Wars film, Darth Vader seems to confuse the use of "thou" and "you". From my point of view, he uses "thou" in order to let his language appear more ancient and formal. In fact, many people think that "thou" was the more formal pronoun, perhaps because it sounds strange and unfamiliar to them.
The fact that "thou" implies an ancient language could also be the reason why it is often used in modern lyrics which try to create a certain atmosphere.