Wikipedia
Schwanengesang (" Swan song"), D.957, is the title of a collection of songs written by Franz Schubert at the end of his life and published posthumously.
The collection was named by its first publisher Tobias Haslinger, presumably wishing to present it as Schubert's final musical testament to the world. Unlike the earlier Die schöne Müllerin and Winterreise, it contains settings of three poets, Ludwig Rellstab (1799–1860), Heinrich Heine (1797–1856) and Johann Gabriel Seidl (1804–1875). Schwanengesang was composed 1828 and published in 1829 just a few months after the composer's death on 19 November 1828.
In the original manuscript in Schubert's hand, the first 13 songs were copied in a single sitting, on consecutive manuscript pages, and in the standard performance order. All the song titles are by Schubert, as Heine did not give names to the poems. (Reed 259) Tobias Haslinger, Schubert's publisher, collected the songs together as a cycle, most possibly for financial reasons, as Die schöne Müllerin and Die Winterreise collections sold very well. Taubenpost is considered to be Schubert's last Lied.
Franz Liszt later transcribed these songs for solo piano.
Schubert also set to music a poem named Schwanengesang D744 by Johann Senn, unrelated to this collection.