Das Lied von der Erde (“The Song of the Earth”) is an orchestral song cycle for two voices and orchestra written by Gustav Mahler between 1908 and 1909. Described as a symphony when published, it comprises six songs for two singers who alternate movements. Mahler specified that the two singers should be a tenor and an alto, or else a tenor and a baritone if an alto is not available.^[1] Mahler composed this work following the most painful period in his life, and the songs address themes such as those of living, parting and salvation. On the centenary of Mahler’s birth, the composer and prominent Mahler conductor Leonard Bernstein described Das Lied von der Erde as Mahler’s “greatest symphony”.^[2] As with his later Symphony No. 9, Mahler did not live to hear Das Lied von der Erde performed.

https://en.wikipedia.org/wiki/Das_Lied_von_der_Erde