How is the music of Dvořák's Symphony No. 9 best described?

Dvořák's Symphony No. 9, commonly known as the "New World Symphony," is best described as a symphony because it is a large-scale orchestral work typically structured in four movements. The symphonic form has a rich history in classical music, characterized by its complexity and use of multiple instruments to create a cohesive and expansive sound. Dvořák's piece aligns with this tradition, showcasing a range of thematic material and emotional depth that exemplifies the symphonic genre.

While concertos focus on a solo instrument accompanied by an orchestra, chamber music involves smaller groups of instruments often with intricate interplays and dialogues, and opera combines music with theatrical elements and voice, Dvořák's Symphony No. 9 does not fit into these categories as it is composed for full orchestra, hence is classified specifically as a symphony.