Who developed modern dance and why?

Modern dance is a broad genre of western concert or theatrical dance, primarily arising out of Germany and the United States in the late 19th and early 20th centuries. Modern dance is often considered to have emerged as a rejection of or rebellion against, classical ballet.

Explanation:

It began to develop during the late 19th century as a protest against classical ballet. It is often said to have been pioneered by Isadora Duncan. In Europe and the USA, such innovators as Rudolph von Laban, Ruth St. Denis and Ted Shawn attempted to make dance a viable contemporary art form