Irish step dancing, popularized in 1994 by the world-famous show Riverdance, is notable for its rapid leg and foot movements, body and arms being kept largely stationary. The solo stepdance is generally characterised by a controlled and rigid upper body, straight arms and back, and quick, precise movements of feet and legs. The solo dances can either be in "soft shoes" or "hard shoes". Soft shoes are often called ghillies or pumps. They are constructed of very soft kid leather - similar to ballet shoes in texture. Their laces crisscross across the top of the feet and are tied up either around the ankle or under the arch of the foot. Hard shoes are often called heavy shoes or jig shoes. They are used to create the beautiful rhythmical percussions. They are made of black leather with fiberglass heels and taps on the tips of the shoes with a leather strap across the top of the foot.