Music produced by Charles Ives reflects an impact of economy on art. After finishing Yale University he has realized that his ideas about music are not popular and won't provide support for his family. Therefore he has entered a business field and left music for his personal enhancement. This allowed his freedom of expression independently from public opinion. As a result he has created first works with using polytonality, (two keys or tones sounding simultaneously) and creating high dissonance. Because he followed his believes about composition and his music wasn't influenced by demands of patron or public most of his music became popular only fifty years later. He was awarded Pulitzer Prize for his Third Symphony 40 years after it was composed.
Another important effect economy had on the music of 2oth century is a disappearing line between high and popular art. Composers start to create popular music and serious music simultaneously, creating high art for own enhancement and commercial art for financial benefit.
An example to this is Philip Glass, who composes serious work, such as Concerto Grosso (1992), and first great minimalism opera Einstein on the Beach (1976), as well as music for the popular films, such as Candyman or The Truman Show.
An example of political influence on the music of 20th century is seen in music by Bella Bartok. He was native to Hungary and was a strung nationalist during his life. After the invasion of Germany in the World War II he banned performance of his music in Germany and Italy. He studied Hungarian folk music and incorporated its motives in his works. In the fourth movement of Concerto for Orchestra (1943) he tells a history of his country. At first we hear a lovely Hungarian motives presented by solo instruments in pentatonic...