Indeed, 20th century composers started the practice of consciously building new scales to aid composition, a seemly logical approach which is nonetheless the reverse of historical precedent. Despite their fundamental role, scales maintain an aura of inexplicability.
Broad definitions are ineffective information filters.
Complicated definitions can be difficult to grasp. Experimentation and intuition are often easier routes to results. In an effort at both order and simplicity, we present a simple graphical model of the musical scale. It consisted of four tones, the highest and lowest always separated by a perfect fourth. Different scales can be created by using different combinations of these three basic tetrachords.