Every hip-hop fan knows the images: The Notorious B.I.G. rocking the "King of New York" crown, Tupac Shakur with the double-finger salute, Jay-Z peeking through his hands as he throws his diamond up.

Hip-hop, along with creative dance and folk dance, is listed as a “dance of contemporary rhythmic expression” in junior high school health and physical education materials, which are based on ...