The beat is the basic unit of time in music, the pulse of the mensural level (or beat 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.^{[citation needed]} This is a distinct and separate use of the term from the way "beat" 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 (often called "strong" and "weak") 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.

The downbeat is the impulse that occurs at the beginning of a bar in measured music. Its name is derived from the downward stroke of the director or conductor's baton on the first beat of each measure. It frequently carries the strongest accent of the rhythmic cycle. However, in some cases, the downbeat may not be emphasized. Such departure from the normal stress pattern of a measure is a form of syncopation.

Backbeat is a term applied to a rhythmic accentuation on even beats.

Backbeat may also refer to:

Music is an art form whose medium is sound and silence. Its common elements are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics, and the sonic qualities of timbre and texture. The word derives from Greek μουσική (mousike; "art of the Muses").

The creation, performance, significance, and even the definition of music vary according to culture and social context. Music ranges from strictly organized compositions (and their recreation in performance), through improvisational music to aleatoric forms. Music can be divided into genres and subgenres, although the dividing lines and relationships between music genres are often subtle, sometimes open to individual interpretation, and occasionally controversial. Within "the arts", music may be classified as a performing art, a fine art, and auditory art. There is also a strong connection between music and mathematics.

To many people in many cultures, music is an important part of their way of life. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound." Musicologist Jean-Jacques Nattiez summarizes the relativist, post-modern viewpoint: "The border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus ... By all accounts there is no single and intercultural universal concept defining what music might be."