Modern classical music is music written in the 20th century and beyond. Although much of it draws heavily on earlier forms, modern composers also experimented with rejection of long-held ideas; notably, Arnold Schoenberg questioned the traditional notions of harmony with his twelve-tone system[?], and John Cage questioned the very definition of music with his use of chance and found sounds.
... 1922), undersea explorer
Francisco Pizarro, (1471-1541), conqueror of the Inca Empire
Marco Polo, (1254-1323), travelled to China in the 13th century.
John Wesley Powell, ...