Du allein weisst was es bedeutet [You alone know what it means]
– annotation by Mahler on the manuscript of the symphony

When the Austrian composer Gustav Mahler died in May 1911 aged only 50, he left two completed but unperformed works: the symphonic song-cycle Das Lied von der Erde [The Song of the Earth] and the Ninth Symphony. Both works were given posthumous first performances by Mahler's close friend and prot é g é , the conductor Bruno Walter: Das Lied von der Erde in Munich in November 1911, and the Ninth Symphony in Vienna in June of the following year. In addition to these two compositions, Mahler left sketches and manuscripts for an incomplete Tenth Symphony.