Final answer:
Composers in the twentieth century drew inspiration from folk and popular music from all cultures, European art music from the Middle Ages through the nineteenth century, and the music of Asia and Africa. They were influenced by the Romantic era but also explored new musical idioms. The rise of the middle class and the increasing demand for music as entertainment also shaped their compositions.
Step-by-step explanation:
Composers in the twentieth century drew inspiration from a variety of sources including folk and popular music from all cultures, European art music from the Middle Ages through the nineteenth century, and the music of Asia and Africa.
The Romantic era in the nineteenth century influenced many composers in the twentieth century, but they also sought to break away from Romanticism and experiment with new musical idioms.
Additionally, the rise of the middle class and the increasing demand for music as entertainment played a role in shaping the compositions of twentieth-century composers.