This is what we found on Wikipedia regarding the Riverdance:

Dance is an art form, often classified as a sport, consisting of sequences of body movements with aesthetic and often symbolic value, either improvised or purposefully selected. Dance can be categorized and described by its choreography, by its repertoire of movements or by its historical period or place of origin. Dance is typically performed with musical accompaniment, and sometimes with the dancer simultaneously using a musical instrument themselves.

An important distinction is to be drawn between theatrical and participatory dance, although these two categories are not always completely separate; both may have special functions, whether social, ceremonial, competitive, erotic, martial, sacred or liturgical. Other forms of human movement are sometimes said to have a dance-like quality, including martial arts, gymnastics, cheerleading, figure skating, synchronized swimming, marching bands, and many other forms of athletics. Dance is not solely restricted to performance, as dance is used as a form of exercise and occasionally training for other sports and activities. Dance has become a sport for some, with dancing competitions found across the world exhibiting various different styles and standards. Dance has an aesthetic appeal to many people.