How did Arnold Schoenberg impact music in the early 20th century?

Arnold Schoenberg was an Austrian composer and painter. His music in the late nineteenth century and the early twentieth century was of profound importance, for he developed the highly celebrated twelve-tone technique. He was also known to be the master of developing variation construction principle.

Explanation:

changeable lenses of different focal lengths allow light to enter the camera, which then forms the image on light-sensitive film" is the one among the following statements about working principle behind a basic still camera is true.