What is the larger importance of Mozart’s work as a product of his historical time and place, and why does his art remain important beyond 18th century Austria?

What is the larger importance of Mozart’s work as a product of his historical time and place, and why does his art remain important beyond 18th century Austria? In other words: why is the history of Mozart’s work—which is almost completely apolitical—so deeply historically important? Please quote the lecture, the reading and a scene in Amadeus (1984). (500 words)

Please don’t use filler but have everything support the fact that Mozart’s work was historically important as it showed the development of a real working class and showed a young man who wasn’t a nobleman, creating great things.