From birth and throughout life, we draw on the non-verbal register of song-and-dance as a primordial form of communication. Infants respond to the musical elements of human speech with dance-like movements that keep time with the music. This interaction recruits them into the human linguistic community, and sets the stage for the later acquisition of verbal speech, which is layered over this foundation of non-verbal, musical communication. Not long after birth, this register of communication is joined by a visual track involving the face and eyes: infants need the faces within their field of view to be responsive to them if they are not to fall into a state of isolated despair and inertia.