Golden ratio

A division of a line into two parts such that the ratio of the smaller part to the larger is the same as that of the larger to the whole (0,618 to 1). The arithmetical expression of golden ratio is a ratio between the succesive elements of the Fibonacci series (a sequence of numbers in which each is the sum of the previous two: 0, 1, 1, 2, 3, 5, 8 etc.). Some 20th-century composers, as Debussy and Bartók, used this principle to shape the musical form of their works.