Which composer's 'unfinished' symphony has only two movements?

Schubert's Eighth, written in 1822 and left with two complete movements, a piano sketch of a third and nothing else. He lived another six years, wrote a great deal, and never went back to it - and he gave the manuscript away to a friend, whose family kept it in a drawer for over forty years until it was performed in 1865.

Why he abandoned it is unknown and the explanations are guesses: illness - he contracted syphilis around then - a sense that the two movements were complete in themselves, or simply moving on. Both movements are in triple time, which is unusual and may be why a scherzo felt redundant.

Schubert's whole career has that shape. He wrote something like 1,500 works before dying at 31, most of them unpublished and unperformed, and much of his greatest music - the last three piano sonatas, the string quintet, the Ninth Symphony - was written in his final year or discovered afterwards. Schumann found the Ninth in a pile of manuscripts at Schubert's brother's house eleven years after his death. He is buried, at his own request, next to Beethoven, whose funeral he had attended as a torchbearer the year before his own.