Atonality

A work of music is atonal if it lacks a key. Generally, this is accomplished by using all twelve tones of the chromatic scale in equal proportion. This technique was pioneered in the 20th century by Austrian-American composer Arnold Schoenberg. With few exceptions, atonal music is generally inaccessible to the average listener, and thus remains controversial. In fact, it was banned in Nazi Germany for being "degenerate" art.