Moderately, not rushed, Sonata form. Flutes and sleigh bells open the unusually restrained first movement (and used later with a melodic theme known commonly as the \u2018bell theme\u2019, which helps define sections throughout the movement) often described as possessing classical poise. As would be expected for the first movement of a symphony, the first movement of Mahler\u2019s Symphony No. 4 is in sonata form.
A listening guide of Symphony No. 4 - 1st Movement with Lew Smoley.