What separates hip hop dance from other forms of dance is that it is often improvisational (freestyle) in nature and hip hop dancers frequently engage in battles—formal or informal one on one dance competitions. Freestyle sessions and battles are usually performed in a cipher, a circular dance space which forms naturally once the dancing begins. It was DJ Afrika Bambaataa that outlined the five pillars of hip hop culture including breaking as one of them (along with rapping, DJing, beatboxing, and graffiti).
The dance industry responded to hip hop dance by creating a more commercial version of it. This "studio hip hop", sometimes called new style is the kind of hip hop dancing seen in most rap and R&Bmusic videos. Technically speaking, hip hop dance (new style hip hop that is) is characterized as hard hitting. The feet are grounded, the chest is down, and the body is kept loose so that a dancer can easily alternate between hitting the beat or riding through the beat. This is in contrast to ballet or ballroom dancing where the chest is upright and the body is stiff. In addition, new style hip hop is very rhythmic and there's a lot of emphasis placed on musicality—how sensitive your movements are to the music.
Tap dance is a form of dance in which the shoes worn by the dancer, known as tap shoes, are used as percussive instruments. The percussive sounds are made by metal "taps" on the heel and toe of each shoe.
Most of his career has been in theatre; however, in 2008 he served as a mentor on Bravo's reality competition Step It Up and Dance. In 2005 he won a Tony Award and a Drama Desk Award for Outstanding Choreography for La Cage aux Folles.