Science from Harvard on how we look as we play the piano versus the sound:

http://news.harvard.edu/gazette/story/2013/08/the-look-of-music/

"Even with professional musicians, who are trained to use sound, and who have both expertise and experience, it appeared that the visual information was overriding the sound.”

This is why we discuss facial expressions, gestures, how we approach the piano, smiling, and looking good as we play. It counts!