Orchestral music in the 20th century underwent radical transformations and was marked by experimentation and a wide range of musical styles, from late-Romanticism to avant-garde, minimalism, and beyond. 

Orchestration expanded with the inclusion of new instruments, electronic elements, and extended techniques, creating unique soundscapes. Influences from jazz, folk music, and popular culture were incorporated, while the symphony and concerto forms evolved. 

Iconic composers like Stravinsky, Schoenberg, Gershwin, and Bernstein contributed to this era of innovation and diversity in orchestral music.