Music: Sound arranged for instruments or voices, for many purposes, exhibiting a great variety of forms and styles. It can be split into categories, including rock, jazz, blues, folk music, soul music, rap, house music, and country and western. Within classical music, there are distinct historical periods - medieval music (1100-1400), Renaissance music (1400-1600), Baroque (1600-1750), classical music (1750-c.1800) and Romantic (c.1800-1900) (see romanticism). In the 20th century, various techniques developed, notably serial music, twelve-tone music and impressionism. Composers also experimented with electronic music.
"Music." Philip's Encyclopedia 2008. London: Philip's, 2008. Credo Reference. Web. 20 February 2012.