Duke Ellington (1899-1974) stands as one of the most consequential composers in American music history. His output spans nearly five decades of sophisticated jazz compositions, orchestral works, and popular songs that elevated the genre far beyond its origins. Ellington's harmonic innovation, gift for memorable melody, and ability to write idiomatically for every instrument he encountered made him a towering figure in twentieth-century music. His influence extends across jazz, classical, and popular music education, where his works continue to teach musicians about composition, arrangement, and the power of swing.