Music communicates to us emotionally through systematic violations of expectations. These violations can occur in any domain—the domain of pitch, timbre, contour, rhythm, tempo, and so on—but occur they must. Music is organized sound, but the organization has to involve some element of the unexpected or it is emotionally flat and robotic. Too much organization may technically still be music, but it would be music that no one wants to listen to. Scales, for example, are organized, but most parents get sick of hearing their children play them after five minutes.
