Go here. The painting is "Carriage House" by Marc Hanson, one of the finest landscape painters around. Marc, himself, raised the question about whether the painting being divided in half is troublesome. We would not question the beauty of this piece. The superb craftsmanship, masterful drawing, sensitive interpretation, deep conviction and a presentation of one of the most beautiful patterns of dappled light I've seen anywhere. But why would he ask the question?
It's not that rules should dominate or that we must be slave to principles, it's to do with the rhythms within the human body and what we feel we need to see or hear in a work of art. It's all about rhythms which are all about intervals.
An interval is a space between two things or a period of time between two events or a pitch between two tones or a degree between two values or colors or intensities. When many intervals are equally spaced, we have a type of staccato response, but when two or three or even four intervals are equally spaced, we feel both bored and restive.
In music, a series of quarter notes without any variation drives us looney. In painting, equally spaced images or divisions feel abnormal, unresolved. We feel ambiguity. We want more space in one shape and less in another. We want a rhythm that is most akin to our heartbeat or our walking pattern or our breathing. We want what nature wants and provides all around us: patterns made from unequal intervals. And it's within nature that we find our most ingenious principles of composing. And that's the reason "blah, blah, blah" is so expressive.