Practice makes perfect, as does starting young. Both adages apply especially to dance. Love of music, a good sense of rhythm and the right physique are not enough. Dancers have to have discipline and be prepared to practice until it hurts, every day. Scientists at the Sport University in Bielefeld have now questioned whether mechanical practice - that is, constant repetition and correction of series of motion - are really the key to success. Their idea was that mental training might also help dancers. They used photographs of ballet dancers in action, with details of pirouettes and other movements. The subjects then sorted the individual images on a computer monitor. The order told the scientists whether the subjects were making fundamental errors in their understanding of the motion. Overcoming the obstacles in the brain could improve dancing on the stage. We went to find out if the mental dance training method really works.