Tap dancing developed into the form

Tap dancing developed into the form we recognize today in the early 20th century. Metal taps were added to dance shoes, a number of new techniques were perfected. One of the most important was the change from the flat-footed step to dancing on the balls of the feet. This is commonly attributed to dancer Bill Robinson. Another was the “cramp roll,” in which the dancer would rapidly move from the ball of the right foot to the ball of the left, then to the heel of each foot. This separation of the steps into distinct areas of the foot, an innovation by dancer John Bubbles, allowed dancers to improvise even more new patterns. Slides across the floor movements up down stairs further enlivened tap. So did relaxed arm shoulder movements. Challenges became a common part of dance routines, with dancers competing very hard to outperform（胜过）each other with new difficult steps.