Book excerpt: It's a dance, dance, evolution! Get to know the plie, arabesque, and other basic steps, and see how ballet has changed over the years. From Anna Pavlova to Mikhail Baryshnikov to Misty Copeland, discover the dancers who added their signature style to this graceful dance form. Go behind the curtain to see what it takes to become a prima ballerina and how a performance comes together.