In music and music theory, the beat is the basic unit of time, the pulse of the mensural level. In popular use, the beat can refer to a variety of related concepts including: tempo, meter, rhythm and groove. In modern pop music, the term "beats" has been used to describe whole pieces of composed music. This is a distinct and separate use of the term from the way it is used traditionally as related only to the rhythmic element of music.
Rhythm in music is characterized by a repeating sequence of stressed and unstressed beats and divided into bars organized by time signature and tempo indications.
Metric levels faster than the beat level are division levels, and slower levels are multiple levels. See Meter (music)#Metric structure.