The Quartet begins by playing the melody in unison at a mezzo forte dynamic. There are clear, authentic cadences after each presentation of the melody. The are often PACs with the tonic in the first violin, often resolving Ti to Do. It is then repeated at a louder and more vigorous dynamic. The main motive is then passed around a little bit, and while the violins have a moving upper line, the melody is handed to the cello while running eighth notes continue in the viola and second violin.
The sweeping triple meter of the Allegro Con Brio gives the sense of of elegance and luxury, this is the type of music that I can picture being played in a small chamber setting for a large, lavish party of some type. When I researched the piece a little bit more, I learned that this is the first of four quartets that Beethoven composed in honor of one of his faithful patrons, so it probably was composed for entertainment purposes.
I like the way that the theme is handed around the quartet, even in the first twenty bars of the movement, and the nature of the piece is very expressive and soloistic which I love. I don't know the date on the piece, but there are moments when the four instruments move together chromatically, and the sometimes surprisingly vigorous Forte dynamics lead me to believe that it was probably in Beethoven's third period that he composed this piece.
Even in the first 1-20mm it shows traces of chromaticism and louder dynamics which is a sign of Beethoven's breaking away from the conventional things that his musical peers were doing at this point.