Which principle is concerned with the repetition of elements to create harmony?

Rhythm is the principle of art concerned with the repetition of elements to create a sense of organised movement and harmony. Just as rhythm in music is created by repeating beats, pauses, and melodic patterns, visual rhythm is created by repeating lines, shapes, colours, or textures at regular or varied intervals. This repetition guides the viewer's eye through the composition in a flowing, harmonious way.

Balance refers to the distribution of visual weight in an artwork - it can be symmetrical, asymmetrical, or radial, but it is not defined by repetition. Variety involves introducing differences and diversity among elements to prevent monotony; it is the opposite of repetition. Unity is the overall sense of wholeness or cohesion in a work - while rhythm can contribute to unity, unity is a broader principle about all elements working together, not specifically about repetition.

The question specifically asks about repetition of elements creating harmony, which is the definition of rhythm in art.