I'm just reading Diderot's "Le Neveu de Rameau" and practicing Mozart these days. I was struck by the pantomime music scene of the nephew and it revealed to me some of my thoughts on interpreting Mozart. I have this idea that Mozart's compositions are a lot about opera (and I'm far from unique in this view). I'm involved at the moment with a mini-opera for one instrument, in the form of piano sonata K331, full of different characters playing their part. The more I study it from that angle, the more I see how essential it is to know the construction, in order to be precise on how to build the phrases, and to understand the different connections between the elements to know where they belong, because you start a phrase being one personage and end it being another one, or several. It is particularly obvious in the second Minuet movement, where there are clearly different partners in the dance: starting with a reverence from the gentleman in the base, a feminine reverence responding in the soprano and off they go to dance. They are talking, showing the different tones of their conversation or their tender mood in the trio section. The sequence of events is exposed through harmony, structure and different effects such as the contrasting piano-forte parts, or the way he is choosing the registers of the voices.
In the same way, I feel that I am watching a theater when I read le Neveu de Rameau. In Mozart its theater in the music language, and in Diderot's in that of thought, but both are about the drama and theater of life.

Getting back to the scene that impressed me: Rameau's nephew playing an imaginary instrument. I find it evidence of how dramatic the music of that time is and I wanted to connect it with a description I read about CPE Bach playing the clavichord, that old and forgotten ancestor of the piano. Just a word on the Clavichord -- the first keyboard instrument that could do a piano and forte dynamic thanks to a direct connection that goes from the key to the string through a metal bar that does not hit the string but sort of vibrates it (which is an effect that string players have but pianist can never have unless they play clavichord) and by putting more or less pressure on the keys you can produce the different dynamics. The sound of this instrument is so delicate though, that you have to be more or less alone in the countryside's silence and in a very small room in order to hear it (which is maybe also a reason it has gone out of fashion, meant for the selected few, not to mention it is the most difficult instrument to play of the keyboard family). The description I read about CPE Bach relates the great impact CPE had on his hearers when playing the clavichord, on how they could perceive great tempests, angry exclamations, and deep anguish through his intensive and passionate playing. CPE Bach was a great influence on all the composers of the classical time and noticeably on Mozart who I believe took all this passion and drama and framed it, made it less wild and more understandable to the public through a theater narrative.