Chord Relationships, or “CRs” for short, are a somewhat obscure but supremely helpful concept to learn (in my own opinion). They are especially helpful and prevalent among film composers. At the core of this concept is the assumption that audiences have come to associate certain chord combinations with specific emotions. For example, a Major chord and a minor chord separated by a major third interval is a super common CR for sad scenes. This CR has a uniquely sad sound to it and can build upon