Notice that both $\left.\text{VII}\right.$ (the “subtonic triad”) and $\left.\text{vii}^{\circ}{}\right.$ (the “leading–tone triad”) are included. The subtonic triad ($\left.\text{VII}\right.$), built on the lowered $\hat{7}$ that occurs in natural minor, regularly occurs in circle of fifth progressions in minor and in rock and pop music, while the leading–tone triad ($\left.\text{vii}^{\circ}{}\right.$), built on raised $\hat{7}$ , is usually either a passing harmony or has dominant function.