A window can let us in on the plentiful possibilities that await us. Its transparency is its greatest asset in accomplishing this task.
Musical form acts in this way for us. Sonatas, jazz standards, theme and variations, and pop songs have transparency in their form. We know we’ll have an exposition, development, and recapitulation. We know we’ll have the head and then the solos followed by the head.
Through this familiar frame we have the luxury of glancing through onto musical genius.