Mozart's music will trigger him into manifesting his powers, which Edna Mode uses to design a new suit that has sensors and a hand-held monitor, which alerts his family to upcoming use of his powers and allows them to counter them quickly.
One of the few things that can calm him down is his mother and the rest of his family. He also becomes enraged if he is given a cookie and is not allowed more. For instance, Jack-Jack loves Mozart's music to the point where he is stimulated by it. Like many infants, Jack-Jack's emotions are unpredictable and since his powers are stimulated by them, being with him when the baby uses his powers becomes very difficult when attempting to pacify or restrain him. He laughs and giggles a lot but cries whenever he is disturbed.
