In this chapter, Schaeffner explains why the origin of musical instruments must be sought in the human body, bodies which “might well have been able to grasp the rudiments of music if they were guided by their first dancing or laboring gestures.” Rhythmic noises come from people “beating parts of their torso or arms,” and the foot striking the ground. Nuances of timbre depend on whether the sole, the heel or the ball of the foot is used. The natural consequence of this is for the body, hands or feet to wear sounding ornaments. Thus “the human body envelops itself in music,” in the form of jingles, attached to feet; maracas and rattles as extensions of wrist movement; castanets, crotala and cymbals that extend handclapping. The author introduces the role played by different forms of cavity in musical instruments, “an essential facet of organology,” and of “the universal importance of the resonator,” which is “at the origin of all instrumental music, together with gestures of the human body.”