 Starting from C, they are obtained by moving six steps (around the circle of fifths) to the left and six to the right.Each step consists of a multiplication of the previous pitch by 2/3 (descending fifth), 3/2 (ascending fifth), or their inversions (3/4 or 4/3).Between the enharmonic notes at both ends of this sequence is a pitch ratio of , or about 23 cents, known as the Pythagorean comma.