Symmetry is one of the most fundamental principles of nature, and also forms the basis of music. Symmetry is the idea that one aspect of a system can change while another remains constant.
This principle is also responsible for music, in that our enjoyment of tonality, melody, harmony and rhythm comes from our subconscious appreciation of different types of patterns (i.e. symmetries) in sound waves.
Max Cooper and Kevin McGloughlin @ maxcooper.net