Caprice no. 8 is a delight! I've learned to savor these slower, singing numbers, as they give you the time and space to enjoy the sound of your viola. I did take the largo marking with a grain of salt however: I believe in movement, even with slower tempos.
This caprice is fairly straightforward. There are a few places that highlight Campagnoli's attention to detail, and underscore my belief that he meant exactly what he wrote. At mm. 5, 6, 17, 18, and others further on, he gives the bass notes only an eighth note, and an eighth rest as the melody continues to sing. This is to say, he is not leaving the choice to you as to whether you should hold the bottom line or not! Remember in Caprice no. 7, the bass notes have full value. The difference in the sound and character is distinct.
One of my favorite parts of this piece is the change from minor to major at m. 17. It is such a sweet moment, and he marks con espressivo to highlight the mood change.
In fact there are a surprising number of expressive and dynamic markings in Caprice number 8. Notice the dolce at measure 5, the outburst of dynamic markings from measure 25-end, and the abundance of hairpins throughout.
Clearly Campagnoli had some feelings for this piece in particular. I wonder if there was a story behind it!