Just an aside. General concensus has often been that the "Sonata Form" movement does not occur until the final movement. In reality, the first movement is somewhat a "Slow Movement Sonata Form" which is sonata form without development. (This idea comes to me from Charles Rosen's books, "Sonata Forms" (yes plural), and his book on Beethoven's Sonatas).
Unfortunately too many have made issue of sonata form by melody (Primary, subordinate, fragmentation, return of main theme, etc) and have missed that there is another equally characteristic (and even more fundamental) aspect to sonata form, and that is the pattern of tonal excursion:Section ---------------Tonal Features
Exposition ------------Duality (Often: Tonic -> Dominant)
I believe the 1st mouvement is not in
sonata form, neither thematically nor tonally. In fact, in his book The Classical Style: Haydn Mozart Beethoven
, (pg. 91) Charles Rosen descibes the Op.27, No.2, i: this way, "That some form of resolution of symmetrical resolution was felt as essential to the sonata (and to almost everything else) is unquestionable: in the rare cases where the material implied either a markedly asymmetrical resolution, or a form (like that of the Moonlight
Sonata) that is relatively unarticulated, the result was a Fantasy."
I am most impressed with A. Schiff's connection of this movement to the Mozart Don Giovani
and funeral march features. This I will certainly take away for evermore!
I would add that Rosen's seeming use above of symmetry as a sine qua non
of Sonata Form, is easily refuted on two counts: 1. there is no form more pure and symmetrical than the ternary form (ABA), not Sonata form, 2. if "symmetrical resolution was felt as essential to the sonata (and to almost everything else)" is as ubiquitous as suggested, then it is not characterisitc in particular. (If the answer is the same for everything, then it answers nothing.)
My 2 cents. Thanks to all for this interesting discussion.