Gustav Mahler (7 July 1860 – 18 May 1911) was a Bohemian-born Austrian composer and conductor. He was best known during his own lifetime as one of the leading orchestral and operatic conductors of the day. He has since come to be acknowledged as among the most important late-Romantic composers, although his music was never completely accepted by the musical establishment of Vienna while he was still alive. Mahler composed primarily symphonies and songs; however, his approach to genre often blurred the lines between orchestral Lied, symphony, and symphonic poem.

Gustav Mahler was born into a German-speaking, Ashkenazic Jewish family in Kaliště (in German, Kalischt), Bohemia, then in the Austrian Empire, today in the Czech Republic, the second of fourteen children, of whom only six survived infancy. His parents soon moved to Jihlava (in German Iglau), where Mahler spent his childhood. Having noticed the boy's talent at an early age, his parents arranged piano lessons for him when he was six years old.

In 1875, Mahler, then fifteen, was admitted to the Vienna Conservatoire where he studied piano under Julius Epstein, harmony with Robert Fuchs, and composition with Franz Krenn. Three years later Mahler attended Vienna University, where Anton Bruckner was lecturing. There he studied history and philosophy as well as music. While at the university, he worked as a music teacher and made his first major attempt at composition with the cantata Das klagende Lied. The work was entered in a competition where the jury was headed by Johannes Brahms, but failed to win a prize.