Craig Wright's Listening to Music course at Yale traces how the symphony grew from Mozart's chamber-sized ensembles into the massive orchestras of the late nineteenth century. He walks through changes in string, woodwind, and brass sections, showing how instrument design and manufacturing let orchestras expand in size and volume, and how concert halls had to be built or rebuilt to hold them. Musical excerpts from Mozart, Tchaikovsky, Dvorak, and Wagner illustrate the shift toward bigger sound and more complex orchestration. The back half of the lecture centers on Gustav Mahler, treated as the culmination of this expansion, with Wright connecting the growth of the orchestra to broader industrial and cultural changes in nineteenth-century Europe. The lecture closes with reflections on how large an orchestra can practically get before the format breaks down. It is lecture 20 of Yale's MUSI 112, recorded in fall 2008, and works as a history of orchestral scale as much as a study of any single composer.