This is, by far, Mozart's most sublime composition:
All joking aside, the video does sum up Mozart and his music quite nicely. I think especially of the segment starting at 1:12 that occurs in what could be Church, where all of the vainly over-dressed lords and ladies of the 1700s peel back to reveal Mozart at the center. Yes, that captures his music perfectly, because at that center of Amadeus's music there is not Deus, but the man himself, and it is decorated very sweetly with all of the frills of 18th century architecture and dress. Mozart's music is essentially a pretty ode to the essentially vain, but still tasteful, humanity of the 18th century.