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.
... is spread out with 20.5% under the age of 18, 6.1% from 18 to 24, 24.6% from 25 to 44, 28.2% from 45 to 64, and 20.7% who are 65 years of age or older. The median age is 44 ...