Composition in painting means the arrangement of elements and their relationships to one another within the frame of the piece. It is not about the interpretation of a painting, or its emotional content, or its references. It is simply the totality of its abstract visual content (whether it is an abstract painting or a representational one).
I find contrast to be the most useful overarching principle in composition. You can look at many aspects of a painting through the lens of how much or how little contrast you have, and greatly increase your understanding of composition.
We ALL lean towards unity, repetition, and cohesiveness. Yet, often, it is the variety, the off-balance, the tension or discord in a piece that makes it compelling. We do not necessarily see this; we see a piece that we "like" without noticing that it's the VARIETY, the differences, the contrasts that make it strong. This workshop is meant to bring you up against this tendency towards unity, and challenge you to expand towards variety.