When Carl Maria von Weber died in 1826, amongst his belongings was a manuscript which came to be known as “Weber’s Last Waltz” although it was actually by Carl Gottlieb Reißiger an ex-student of Salieri who succeeded Weber as Kappellmeister at the court of Dresden.
This waltz became extremely popular amongst pianists, and is primarily of interest to guitarists because it was the favourite piece of the eponymous Roderick Usher of Poe’s “Fall of the House of Usher”
“his heart is a suspended lute, as soon as it is touched, it resounds” -quote from “Le Refus” (1831) by the French songwriter Pierre-Jean de Béranger (1780–1857)

Roderick composed his own music based on it and the narrator describes it as “a … singular perversion and amplification of the wild air of the last waltz of Von Weber”. The waltz is hardly wild, and Usher plays it on the guitar as the house collapses around him (another literary reference for the ongoing blog), so he must have done something rather special to it to make it sound interesting.
Poe’s tale is a masterpiece of Gothic fiction, with foreboding in every sentence, Roderick’s split personality, a creepy mirroring of Roderick’s poem The Mad Tryst and events around the narrator, a hasty burial of the twin sister etc etc
Here is Reißiger’s original

Not what most people would call wild, which is probably what prompted Nikita Koshkin to write his classic “Usher Waltz”, which is much more the kind of thing you would expect the crazed hypochondriac owner of a crumbling house to improvise (he must have been a good guitarist!)
Here is a video of Asya Selyutina, Koshkin’s wife, playing the Usher Waltz

Interestingly, Johan Kasper Mertz also wrote a piece based on Weber’s last thoughts.
More about Koshkin