Modern dance treats dance as an art rather than a particular style unto itself. It stresses individuality of expression over uniformity of method. A small group of dancers in this country in the 1920s and 1930s are credited with beginning the approach. Within a few decades it had received popular and institutional acceptance. By the 1960s and 1970s, modern dance had become an exciting theater art. The dance form has developed a tradition of independence, individualism, and personal style. Unorthodox movement and new form has been preferred in contrast to an established technical system. Choreographers of one generation formed companies that were training grounds for the next generation.