Carl Maria von Weber is one of my favorite Romantic composers, and not just for
Freischutz. I find also his instrumental music to be extremely appealing. The piano sonatas in particular are perennial favorites in the genre, despite the common criticism leveled at them for being rather disjointed. My joy was all the more greater when a few days ago I stumbled upon this book, edited by
R. Larry Todd, probably the world´s leading expert on
Mendelssohn:

Among the many articles included, the one that picqued my interest the most is
Michael Tusa´s
In Defense of Weber, which offers a sympathetic assessment of his piano music. After pointing out some innovative features of his piano variations, he proceeds to an in-depth analysis of the four sonatas and shows, in rather dry, technical language sometimes impenetrable for me as a non-specialist, that far from being disjointed, there is always an unifying structure and conception behind them. The best case he makes is for the fourth, which according to
Julius Benedict who was
Weber´s pupil, even has a psychological program conceived by the composer himself. It is surprising for me that
Tusa fails to notice, or at least to mention, that the program of the sonata (composed in 1822) matches very closely the mental tribulations of the main character in
E. T. A. Hoffmann´s
The Sandman, published in 1817. Now, whether
Weber had read it is a matter of speculation from my part, but given that (1) he was acquainted with
Hoffmann´s music, having written a sympathetic review of his opera
Undine (read it here:
http://www.raptusassociation.org/hoffm_undinewebere.html) and (2) he was an active member of a literary/artistic association bearing the curious name "Faust´s Descent to Hell", (of which another prominent member was his friend and fellow composer
Franz Danzi) it is not implausible. Be it as it may,
Weber´s own program is clearly reflected in the music. If you are interested I suggest you listen to the whole thing and try to figure it out before discovering the original*. It would be a nice opportunity to hear this neglected pianistic gem.
I have two recordings of it:

Both are excellent in conveying the mood(s),
Endres being slightly better musically, especially in the final movement, and
Olssohn having the better sound. If you are seriously interested in
Weber´s piano music, you should have them both.
*
Tusa´s article can be read almost in full here:
https://books.google.ro/books?id=FWNGAQAAQBAJ&pg=PA146&lpg=PA146&dq=michael+tusa+in+defense+of+weber&source=bl&ots=M0uXqXTKJY&sig=UuP2RV9gWQzjLOwuOoU9evaeTDk&hl=en&sa=X&ved=0ahUKEwid5_rB48zMAhVLkiwKHWMsDgwQ6AEILjAG#v=onepage&q=michael%20tusa%20in%20defense%20of%20weber&f=false (scroll one page down)