Das klagende Lied (Song of Lamentation) is a cantata by Gustav Mahler, composed between 1878 and 1880 and greatly revised over the next two decades.

[1] Mahler began to write the text of Das klagende Lied during the early part of his final year in the Vienna Conservatory, where he was a student between 1875 and 1878.

[citation needed] It is based on "Der singende Knochen" ("The Singing Bone") from the collection by Jacob and Wilhelm Grimm.

In spite of having lavished such detailed effort on revising the work's first part, Mahler then decided (Autumn 1893) to omit it completely.

This manuscript eventually entered the collection of Yale University, from which 'Waldmärchen' became available for public performance after its re-attachment to the then-standard two-movement version of the work.