Nationalism continued to be a strong musical influence in the first half of the century. The study of folk songs enriched the music of numerous composers, such as Ralph Vaughan Williams (England), Bela Bartok (Hungary), Heitor Villa Lobos (Brazil) and Aaron Copland (USA). Jazz and popular musical styles have also been tremendously influential on “classical” composers from both the United States and Europe.
Technology has played a increasingly important role in the development of 20th century music. Composers have used recording tape as a compositional tool (such as Steve Reich’s Violin Phase). Electronically generated sounds have been used both on their own and in combination with traditional instruments. More recently, computer technology has been used in a variety of ways, including manipulating the performance of instruments in real time.