さすらい人
An important, unique work for solo piano written by Schubert, stands apart from his sonatas but is closely related to them in its concept and style: the "Wanderer Fantasy" of 1822. The harmonic scheme inherent in each of Schubert's last sonatas, according to Charles Fisk, of a tonal conflict gradually resolved through musical integration, finds its precedent in the "Fantasy". Moreover, a tonal stratum which plays a unique role throughout the sonata trilogy – C minor/F minor, is also precedented in the "Fantasy" as well as the song on which it was based, "Der Wanderer" (of 1816) (Fisk calls C minor "the wanderer's key"). In these two earlier works, and likewise in the last sonatas, passages written in the C minor/F minor stratum portray a sense of alienation, of wandering and homelessness, according to Fisk. The allusion to the song "Der Wanderer" becomes fully explicit when, in the development section of the B Sonata's opening movement, the new theme first presented in this section, undergoes a transformation (in bars 159–160) to become an almost literal quotation of the song's piano introduction.