Claude Debussy was a French composer whose works have been a seminal force in the music of the 20th 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 importance as a composer is due to this own achievements and by the paths he opened for others to explore, hence the homage to him paid by later composers such as Boulez. His major works include Clair de lune, 1890–1905), Prélude à l'après-midi d'un faune, the opera Pelléas et Mélisande (1902) and La Mer (1905; ‘The Sea’).