Symphony No. 9 in D Minor — Ludwig van Beethoven

Beethoven's 1824 Symphony No. 9 remains the most revolutionary symphonic achievement, introducing choral voices to the form with its 'Ode to Joy' finale—a universal hymn completed while he was nearly deaf. It sold over 1.5 million copies in its first century of recordings, solidifying its status as a transcendent work. Its climactic theme, performed at pivotal global events, rivals Beethoven's own Fifth Symphony in cultural ubiquity but surpasses it in sheer visionary impact.