ABSTRACT
Scales and intervals The number of scales in general use in European music has varied considerably over the centuries. In the heyday of modal music in the Middle Ages there were the modal scales of the Gregorian system, each containing the same seven intervals but in a distinctive order, which gave each mode its own characteristic sound. In time all but two of them, which evolved into our major and minor scales, were virtually forgotten. That was the situation until the late nineteenth century, which brought experiments with strange scales such as the whole-tone, strange intervals such as the quarter-tone and sixth-tone, and the ultimate resort of atonality, which is, in effect, the abandonment of the concept of a scale.
