Classical ballet began in 1653 under King Louis XIV as a court dance. Through the years it has transformed into a sophisticated, highly-trained dance form where men can make fantastic leaps and multiple turns and women articulate their feet in elegant pointe work, high extensions and pas de deux (partnering).
Every dancer, no matter what his/her performance style, should take ballet class because ballet is the underlying technical basis for jazz, modern, character, pointe, pas de deux, etc. Ballet barre builds correct alignment, posture, and placement to make a dancer look good while moving.
Fundamentals of ballet provide all other dance forms with body placement and technique for leaps, spotting for turns, and carriage of the arms, head and upper body. A technical, correctly-taught ballet class builds body strength and muscle memory as well as helping the brain memorize dance combinations more rapidly.
Learning to work in a corps de ballet builds team-work, cooperation, musicality, and a realization of the dance space around each dancer.