In tonal Western classical music (music with a tonic key or "home key"), the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, and intervals of a third and a fifth above the root note. ... A series of chords is called a chord progression
3 variety of shapes because none of them are smetracal texture doesn't matter in art and it all black and white so i dont think unity of colors would apply