The third movement, in A–B–A structure, acts as the slow movement in the four-movement plan.
The extra-musical idea behind it is that of a hunter's funeral and a procession of animals that follows.

The initial 1st subject of the A section is based on the popular round "Bruder Jakob" (although Mahler calls it "Bruder Martin") more commonly known as "Frère Jacques"; however, Mahler places the melody in a minor mode.

The subject is first presented by a solo double bass, followed by bassoon, tuba and, eventually, the entire orchestra.
A counter-melody is played over top of the canon in the oboe.

The mood changes, and the 2nd subject, one of the most distinctive portions of this symphony follows.
Mahler uses cymbal, bass drum, oboes, clarinets and a trumpet duo to produce the sound of a small klezmer band; Mahler's use of klezmer is sometimes credited to his Jewish roots.

After a brief return to the 1st subject, a more contemplative B section, in G major ensues, featuring material from the fourth of Mahler's Lieder eines fahrenden Gesellen, "Die zwei blauen Augen".

After the B section ends, the A section is repeated in a varied form.
 The 1st subject returns in E-flat minor.
 Then the 2nd subject is heard again, and after a while, the music modulates back to D minor, and Mahler incorporates all three thematic elements on top of each other.
 The final few bars of the 2nd subject is heard next, and once again, the 1st subject appears briefly for one last time in D minor, and the movement ends with simple alternating fourth in the lower strings, notably the key motif from the first movement.
The third movement, in A–B–A structure, acts as the slow movement in the four-movement plan. The extra-musical idea behind it is that of a hunter's funeral and a procession of animals that follows.
The initial 1st subject of the A section is based on the popular round "Bruder Jakob" (although Mahler calls it "Bruder Martin") more commonly known as "Frère Jacques"; however, Mahler places the melody in a minor mode.
The subject is first presented by a solo double bass, followed by bassoon, tuba and, eventually, the entire orchestra. A counter-melody is played over top of the canon in the oboe.
The mood changes, and the 2nd subject, one of the most distinctive portions of this symphony follows. Mahler uses cymbal, bass drum, oboes, clarinets and a trumpet duo to produce the sound of a small klezmer band; Mahler's use of klezmer is sometimes credited to his Jewish roots.
After a brief return to the 1st subject, a more contemplative B section, in G major ensues, featuring material from the fourth of Mahler's Lieder eines fahrenden Gesellen, "Die zwei blauen Augen". 
After the B section ends, the A section is repeated in a varied form.  The 1st subject returns in E-flat minor.  Then the 2nd subject is heard again, and after a while, the music modulates back to D minor, and Mahler incorporates all three thematic elements on top of each other.  The final few bars of the 2nd subject is heard next, and once again, the 1st subject appears briefly for one last time in D minor, and the movement ends with simple alternating fourth in the lower strings, notably the key motif from the first movement.
Symphony No. 1 (Mahler)