Some of my mis-spent youth was spent entering competitive classes at local music festivals (aka competitions). Many of my fellow entrants went to a specialist music school down the road in Wells, where they were apparently taught how to wobble and sway at the keyboard. This used to annoy me, a precocious advocate of the ramrod principle of piano-playing.
Nowadays I can sway for England. (Good thing self-consciousness is not in my vocabulary.) And why not!? A Zambian friend recently attended her first Western Art Music concert in Cambridge and was shocked and perplexed to find the audience still and quiet throughout. Whenever I listen to music at home (which is quite a lot of the time) I am always singing along, doing a little dance, waving about the place, you name it. To Sibelius and Brahms no less than Piazzolla or Ravel. Visitors may view this spectacle for a small fee, if they can stand it...
Despite his fondness for the word gnostics, Peter Leithart has hit something here about (classical) music and movement.