Some months ago I blogged several times about musicians who don't move a lot when they perform. The subject merits repeated study, so let's look at something fantastic.
These two Brazilian guys here are experts on the art of improvising poetry and songs in public, in the style known as "repentista" in Portuguese. (Repentista comes from the word for "sudden.") They are both masters of the art . . . but the guy on the red shirt is exceedingly poised and well directed. You don't have to understand Portuguese to marvel at his back, his calm, his strength, and his communication skills!
Condensed energy is the name of the game.