Aaron Copland (/ˈkoʊplənd/, KOHP-lənd; November 14, 1900 – December 2, 1990) was an American composer, composition teacher, writer, and later a conductor of his own and other American music. Copland was referred to by his peers and critics as "the Dean of American Composers". The open, slowly changing harmonies in much of his music are typical of what many people consider to be the sound of American music, evoking the vast American landscape and pioneer spirit.