|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. It may also be divided among "art music" and "folk music". There is also a strong connection
between music and mathematics. Music may be played and heard live, may be part of a dramatic work or film,
or may be recorded.
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."