Claude Debussy
Music is the space between the notes.
First of all, ladies and gentlemen, you must forget that you are singers.—Instructions to the performers of his opera Pelléas et Mélisande
A noted trend starter in the history of Classical Music, his Prélude à l'après-midi d'un faune is considered as a turning point of classical music, starting the Impressionist movement in classical music, and in many ways the antecedent of Modern and Contemporary Classical music. Needless to say, he was, and still is a highly important and inspiring figure in classical music. His influence to music is as much as Claude Monet's influence to painting. Modern music historians and critics consider himself as the ultimate example, along with his fellow composer Maurice Ravel, of the Impressionist movement.
Outside of his musical success though, his life was kind of turbulent. He had an affair with another's wife although already married, his ex-wife attempted (unsuccessfully) suicide, and produced a huge scandal, so much that he had to flee to England. They had a child, who sadly only outlived her father by only a year, died because of the diphtheria epidemic of 1919. The whole family was buried together.
Inside of the classical circle, his notable pieces include Prélude à l'après-midi d'un faune, La Mer, Preludes, Pelléas et Mélisande... The popular listeners might have heard of Clair De Lune, Arabesque No. 1, Children's Corner...