Math and science are thus special in the sense that their constraints - self-consistency and accurate representation of objective reality - give powerful, direct practical benefits. Other forms of art can have practical use too, e.g. by moving people, or refining their beliefs (or convincing them of lies in the interest of those who commissioned the art - that's advertising and propaganda).
Another way in which math and science are special is that their constraints are independent of humans. Where other forms of art are necessarily a function of how people perceive and feel, the output of science and mathematics is, in principle, universal. I don't know of any other form of art like this.