Schwanengesang was actually Franz Schubert's swan song, and it's a set of miniatures rather than a narrative. Most of the Ludwig Rellstab verses compare images of nature to the poet's desires and longing for a distant love. Each of the seven songs is a discrete event, and the artists were freer with contrasts in tempo and volume.
Brodie, Susan (2016) Inner Life of Schubert's Song Cycles. In: American Record Guide, Vol. 79, No. 1, pp. 15-16. Available at https://openmusiclibrary.org/article/368184/.