"Pacific 231" is a symphonic work composed by Arthur Honegger in 1923. The piece is inspired by the sound and movement of a steam locomotive, specifically the Pacific type engines. It captures the rhythmic and mechanical qualities of a train journey through its dynamic orchestration. The composition is notable for its innovative use of orchestral timbres and its ability to evoke the power and speed of trains. "Pacific 231" is often performed in concert settings and has become a significant example of early 20th-century program music, reflecting the industrial age's fascination with technology and progress.