There is a way to measure harmony. We do it all the time. It stops us, even momentarily when we perceive harmony in a setting, picture, or group. Harmony isn’t required for something to be well made. The subject of disharmony and drama will be addressed later. Harmony, however, is something observable, though it may take some practice.
Imagine that everything has a psychic weight and that no two objects can have that same weight. Stone 1 and stone 2 for instance might seem about equal, they might even be cut identically (like a cobblestone) yet when set side-by-side you would choose one over the other.
Simple enough, you trust that your choice (measurement) was accurate (ridiculous you say). But, if you follow this simple measuring game you will find yourself tallying (as when you build a wall or plant a group of shrubs); you will tally the weights back and forth and if you stop (and still trust that this isn’t complete madness), you may find that you reach the moment of harmony when all the elements are balanced on the scale of the whole image. This does not happen often in nature on a scale that we can perceive (within our visual frame).