2400 years ago Aristotle asked: "Why music being just sounds remind states of human soul?" He listed this question alongside "Is the wolrd finite?" and "Does God exist?" Darwin wrote that music is "the greatest mystery." Music existed in all human societies, but its function in cognition is not known. Many contemporary experts wrote that applied uses of music (in military, in mother-baby talks, in celebrations...) are just that - applied uses of an ability that evolved for some fundamental human need, but what is this need?