The mystics have seen five 'tatwas,' or elements, working behind both the sound and the rhythm, although musicians consider seven notes in a scale. The original scale known to the mystics had five numbers. And there were five kinds of scales among ancient people, with five different classes of rhythm. They took the five colors to represent the five elements. People often say, "This color is lucky and that is unlucky," "This number is lucky and that unlucky." But it is not the particular color or number in itself. It is the harmony of the situation. In what relation does that particular color and number stand to you, your life's affair, your own constitution, your stage of evolution. If it stands in harmony with your life, then it is harmonious and lucky. If not, it is inharmonious and unlucky. But it does not mean that the particular color is harmonious; it is just how it stands in your life that decides whether it is harmonious or not. So it is with sounds.