Aaron Copland (November 14, 1900 – December 2, 1990) was an American composer, composition teacher, and later a conductor of his own and other American music. Referred to by peers and critics as "the Dean of American Composers," he is best known for the works he wrote in the 1930s and 1940s and for his accessible style--often referred to as "populist," and which the composer labeled his "vernacular". These works include the ballets Appalachian Spring, Billy the Kid and Rodeo; Fanfare for the Common Man; and Third Symphony. He also produced music in many other genres, including chamber music, vocal works, opera, and film scores.

After studying for three years with Nadia Boulanger--whose eclectic approach to music inspired his broad taste—he returned to the United States determined to make his way as a full-time composer. However, he found that composing modernist orchestral music, which he had adopted while studying abroad, was not financially sound, particularly during the Great Depression. He shifted in the mid-1930s to a style that mirrored the German idea of Gebrauchsmusik ("music for use"), which could serve both utilitarian and artistic purposes. Copland wanted to find a distinctively American sound. "There is a French-sounding music, a German sound, why not American?” he said. “We had done it in ragtime and jazz, but not in the kind of concert music I was interested in."

During the late 1940s, Copland returned to modernism and adopted the use of the twelve-tone (serial) techniques popularized by Arnold Schoenberg. He incorporated these methods into his Piano Quartet, Piano Fantasy, Connotations, and Inscape.

From the 1960s onward, Copland's activities turned more from composing to conducting. He became a frequent guest conductor of orchestras in the U.S. and the U.K. and made a series of recordings, primarily for Columbia Records. A large portion of his estate was bequeathed to the creation of the Aaron Copland Fund for Composers, which bestows more than $600,000 per year to performing groups.