Mahler pushes his orchestra to emulate the expressivity of the human voice. He marks his parts with very detailed dynamics, bowings, articulations, and other instructions. Here, he gets the cellos to sigh by playing glissando, sliding from one note to the next. In the First Symphony, the rest of the orchestra stand still while the cellos ask a searching question, using the alternation of major and minor harmonies to convey the expressive meaning.

On many occasions in his earlier symphonies, Mahler brought whole passages from his songs into the epic worlds of his symphonies.

Mahler made a daring harmonic leap back to the home key of D Major in the First Symphony’s Finale. He described the creative process that led to the breathtaking moment: Again and again, the music had fallen from brief glimpses of light into the darkest depths of despair. Now, an enduring, triumphal victory had to be won. As I discovered after considerable vain groping, this could be achieved by modulating from one key to the key a whole tone above (from C major to D major, the principal key of the movement). Now, this could have been managed very easily by using the intervening semitone and rising from C to C sharp, then to D. But everyone would have known that D would be the next step. My D chord, however, had to sound as though it had fallen from heaven, as though it had come from another world. Then I found my transition — the most unconventional and daring of modulations, which I hesitated to accept for a long time and to which I finally surrendered much against my will. And if there is anything great in the whole symphony, it is this very passage, which — I can safely say it — has yet to meet its match.

The principal theme in the first movement of his First Symphony was first used by Mahler years before in one of his Songs of a Wayfarer. “I Walked Across the Fields This Morning” (Ging heut’ morgen übers Feld). One morning, striding across the dew-laden fields, the lovelorn narrator briefly escapes from his grief by opening himself to nature. The finch sings to him: “Isn’t it a beautiful world? Well, then?”

Evocations of the sounds of nature, realized through imaginative instrumentation, recur throughout Mahler's works. In "On My Love's Wedding Day" (Wenn mein Schatz Hockzeit macht), the first song of Mahler's Songs of a Wayfarer (Lieder eines fahrenden Gesellen) the narrator finds himself in a countryside that has burst into bloom. High bells illustrate the Blümlein (little flowers) of the text, while solo flute and violin trill like a pair of lovebirds.

Why does Mahler change the call of the cuckoo?

Mahler based the Scherzos of his First and most of his later symphonies on the Ländler, a rustic peasant waltz often accompanied by heavy stamping.

The turn had a long and deep significance for Mahler that dates back to his earliest musical memories. In the synagogue, he would have heard the turn frequently as a ornament in the chanting of the Torah: for instance, in the cantillation called gershayim. He would probably have even sung it while reading the portion assigned to him for his bar mitzvah.