👉 A hierogrammatical is a type of musical notation used in classical music. It consists of an open, closed, and semi-closed circle, with each semicircle representing a different note on the piano or other instrument. In this notation, the open circle represents a major third, the closed circle represents a minor third, and the semi-circular segments represent a fifth, a fourth, and a quarter note. The notes are placed in a regular pattern, alternating between major and minor keys
