Tearing through open spaces and timing each turn to burst out of them, a seeming continuum of drones weaves through a set of obstacles lap after lap, until the stutter of a pilot’s joystick breaks the cadence of this competitive concert and destroys the illusion. It’s the drama — anticipating and reacting to those human moments — that has propelled drone racing from an underground scene in Australia four or five years ago to vying for a place in the sports mainstream today. Drone racing is more than a group of pilots pushing their cinematographic drones from point A to B.