Was a development in western music after 1900?

Yes, a significant development in Western music after 1900 was the rise of atonality and the use of twelve-tone techniques, primarily pioneered by composers like Arnold Schoenberg. This marked a departure from traditional tonal structures, allowing for greater freedom in musical expression. Additionally, movements such as jazz and electronic music emerged, further diversifying the musical landscape and influencing various genres. These developments reflected broader cultural changes and innovations in artistic thought during the 20th century.