In music and music theory, the beat is the basic unit of time, the pulse (regularly repeating event), of the mensural level[1] (or beat level).[2] The beat is often defined as the rhythm listeners would tap their toes to when listening to a piece of music, or the numbers a musician counts while performing, though in practice this may be technically incorrect (often the first multiple level). In popular use, beat can refer to a variety of related concepts including: tempo, meter, specific rhythms, and groove. The Fourth installment of the Elements of music The Melody, The Rhythm, Music, and now The Beat!