Gustav Mahler once said, "With song you can express so much more in the music than the words directly say. The text is actually a mere indication of the... hidden treasure within." Over fourteen years, from 1887-1901, he devoted his compositional output almost exclusively to texts and ideas drawn from a collection of German folk poetry entitled Des Knaben Wunderhorn: Alte deutsche Lieder, resulting in twenty-four songs which heavily inspired his first four symphonies. This study explores Mahler's songs based on this poetry and identifies the connections the composer found between these products of Germany's folk past and his own contemporary environment. The songs he created comment on and engage with Vienna's musical life, Freudian theory, Mahler's religious life, his family relationships, his views on women and romance, economic inequality, and wartime violence. As remnants of a folk tradition, the poems contained in Des Knaben Wunderhorn served the purpose of instructing young people on ways of conducting themselves, just as fairy tales do today. Mahler's adaptation of these stories and his updating of them to serve audiences of his own time demonstrate the universality of the lessons these poems provide, both to audiences of Mahler's day, and also to our own.