Claude Debussy was a French composer whose works were a seminal force in the music of the twentieth century. He developed a highly original system of harmony and musical structure that expressed in many respects the ideals to which the Impressionist and Symbolist painters and writers of his time aspired. His major works include Clair de lune (“Moonlight,” in Suite bergamasque, 1890–1905), Prélude à l’après-midi d’un faune (1894; Prelude to the Afternoon of a Faun), the opera Pelléas et Mélisande (1902), and La Mer (1905; “The Sea”).