Impressionism is an art movement that originated in France in the 19th century, originally and mainly referred to the art of painting, characterized by emphasizing instant impressions and natural light. Impressionism brought a revolutionary change to those who sought precise-artistic-forms and perfection, and spawned many original and forward-looking works. Impressionism also laid the foundation for later art movements, such as Cubism and Abstract Expressionism.
In music, "Impressionism" usually refers to a musical style in which composers attempt to express emotions or feelings through the melody, harmony, and sound of a piece. This musical style is often influenced by Romanticism and philosophical ideas, and places a great emphasis on atmosphere and emotional expression in music.