Schubert's Symphony in D major, D 615, is an unfinished work that survives in an incomplete four-page, 259-bar sketch written for piano solo.
He abandoned this symphony after this initial phase of work and never returned to it, probably due to dissatisfaction with it, although Schubert would live for another ten years.
In the mid-20th century, Dr. Ernst Hilmar discovered in a library in Vienna (the Wienbibliothek im Rathaus) a folio containing works by Schubert, titled "Sinfonie" and dated to May 1818.
In fact the folio was labelled "Zwei Symphonien in D" ("Two Symphonies in D"), indicating that a librarian had previously thought along similar lines around 1900.
Its beginning is somewhat reminiscent of the slow introduction to Haydn's 104th symphony, but it quickly moves into harmonically more remote territory, going as far as the tritone-related key of A♭ major.
Brian Newbould sees a falling off of quality during the exposition, saying that "despite some promising ideas it runs out of wind before Schubert rests his pen".
Newbould comments that "the finale is no less attractive [than the first movement], but perhaps Schubert in the end did not consider its prettiness and tendency to a loose balletic build as the right way forward for a maturing symphonist."