Webthe symphony no 9, in c major d. 944, or the great, was not performed until more than ten years after schubert’s death, while the unfinished, composed in 1822, lay forgotten. Webnew research suggests that franz schubert's 'unfinished' symphony was not left incomplete by the composer himself before his death at the age of 31 in 1828. Webfranz schubert’s symphony no. 8, known as the unfinished symphony, has always been mired in mystery as to why it was never completed by the composer. Webthe mystery of the 'unfinished' symphony. Schubert’s unfinished symphony only came to light more than three decades after the composer’s death when an old man claimed. Webthe thing we find remarkable about the hüttenbrenners' various communications to luib around 1858 is something that is completely missing: Webdescriptionfranz schubert’s symphony no. 8, known as the unfinished symphony, has always been mired in mystery as to why it was never completed by the composer. Webthe most credible explanation is that in late 1822, precisely when he would have moved on to the “missing” movements of the piece, schubert was diagnosed with syphilis. Weban unfinished symphony is a fragment of a symphony, by a particular composer, that musicians and academics consider incomplete or unfinished for various reasons.