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.
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Hogg, P. W., Constitutional law of Canada 4th ed. (Carswell: Scarborough) with Supplement to Constitutional Law of Canada (2002-)
Humphrey, J.P., Human Rights and ...