Schubert's Symphony in D major, D 2B/997, is an unfinished work that survives in an incomplete 30-bar orchestral score. The sketch includes the whole slow introduction and the first theme of the Allegro before breaking off. It is one of Schubert's six unfinished symphonies. It was begun in 1811, when Schubert was fourteen years old, but it is unclear exactly how much he wrote before he abandoned the symphony (despite the fact that he would live another seventeen years). Its instrumentation is for the standard early Schubertian and classical orchestra, with the addition of trombones.