Slow fast slow fast
Here is the last movement of Beethoven's quartet opus 18 number 6, La Malinconia
Here Beethoven created a new form for a quartet movement: the interleaving of a slow, elegaic section with a fast and sprightly one. Beethoven returned to this bipolar form, in different variations, in later quartets (for example, the serioso movement of opus 95, the first movement of opus 127, the first movement of opus 130). It was later a favorite form of Brahms, who used it in his quartets, his sextets, and in the horn trio.
It was a new form. Or, almost a new form. Because Haydn tried it out first. His "Sunrise" quartet, opus 76 number 4. is essentially in this form:
In this movement, there are no tempo markings to separate the elegaic section from the allegro one; but the movement is built on the contrast between the two alternating sections. The opening section is not marked slower, but it is clearly written slower. I am, I suppose, a minority of one for believing that the opening section should be played actually slower - something that the Oberon quartet in this performance hints at by taking large rubatos, though the basic tempo does not change.
It is interesting that both the Haydn opus 76 and the Beethoven opus 18 quartets were written at the same time, and were both dedicated to the prince Joseph Franz Maximilian Lobkowicz. It was the custom in those days to give the manuscript to the dedicatee, who held it for a year or so to share with his friends before publishing it. It is therefore likely that Beethoven and/or Haydn saw the others' quartets in manuscript before publication, and were perhaps inspired one by the other. Is it possible that the last movement of the Malinconia was inspired by Haydn's Sunrise?