Information

Music is an art form in which the medium is sound organized in time. Common elements of music 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.

Greek philosophers and ancient Indians 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, but the opinion of the listener does not necessarily help music theorists formulate a precise definition of music. Like the notion that visual arts must be beautiful to behold, the tacit notion that music need be pleasant to listen to has been questioned.

20th-century composer John Cage was explicit that any sound can be music, saying, for example, 'There is no noise, only sound.' According to musicologist Jean-Jacques Nattiez, '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, except that it is 'sound through time'.'

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.

Performance
Performance is the physical expression of music. Often, a musical work is performed once its structure and instrumentation are satisfactory to its creators; however, as it gets performed, it can evolve and change.

A performance can either be rehearsed or improvised. Improvisation is a musical idea created on the spot (such as a guitar solo or a drum solo), with no prior premeditation, while rehearsal is vigorous repetition of an idea until it has achieved cohesion. Musicians will generally add improvisation to a well-rehearsed idea to create a unique performance.

Many cultures include strong traditions of solo and performance, such as in Indian classical music, and in the Western Art music tradition. Other cultures, such as in Bali, include strong traditions of group performance. All cultures include a mixture of both, and performance may range from improvised solo playing for one's enjoyment to highly planned and organised performance rituals such as the modern classical concert, religious processions, music festivals or music competitions.

Chamber music, which is music for a small ensemble with only a few of each type of instrument, is often seen as more intimate than symphonic works. A performer may be referred to as a musician.

Aural Tradition
Many types of music, such as traditional blues and folk music were originally preserved in the memory of performers, and the songs were handed down orally, or aurally (by ear). When the composer of music is no longer known, this music is often classified as 'traditional'. Different musical traditions have different attitudes towards how and where to make changes to the original source material, from quite strict, to those which demand improvisation or modification to the music. A culture's history may also be passed by ear through song.

Ornamentation
The detail included explicitly in the music notation varies between genres and historical periods. In general, art music notation from the 17th through the 19th century required performers to have a great deal of contextual knowledge about performing styles.

For example, in the 17th and 18th century, music notated for solo performers typically indicated a simple, unornamented melody. However, it was expected that performers would know how to add stylistically-appropriate ornaments such as trills and turns. In the 19th century, art music for solo performers may give a general instruction such as to perform the music expressively, without describing in detail how the performer should do this. It was expected that the performer would know how to use tempo changes, accentuation, and pauses (among other devices) to obtain this 'expressive' performance style. In the 20th century, art music notation often became more explicit and used a range of markings and annotations to indicate to performers how they should play or sing the piece.

In popular music and jazz, music notation almost always indicates only the basic framework of the melody, harmony, or performance approach; musicians and singers are expected to know the performance conventions and styles associated with specific genres and pieces. For example, the 'lead sheet' for a jazz tune may only indicate the melody and the chord changes. The performers in the jazz ensemble are expected to know how to 'flesh out' this basic structure by adding ornaments, improvised music, and chordal accompaniment.

Production
Music is composed and performed for many purposes, ranging from aesthetic pleasure, religious or ceremonial purposes, or as an entertainment product for the marketplace. Amateur musicians compose and perform music for their own pleasure, and they do not derive their income from music. Professional musicians are employed by a range of institutions and organisations, including armed forces, churches and synagogues, symphony orchestras, broadcasting or film production companies, and music schools. Professional musicians sometimes work as freelancers, seeking contracts and engagements in a variety of settings.

There are often many links between amateur and professional musicians. Beginning amateur musicians take lessons with professional musicians. In community settings, advanced amateur musicians perform with professional musicians in a variety of ensembles and orchestras. In some cases, amateur musicians attain a professional level of competence, and they are able to perform in professional performance settings.

A distinction is often made between music performed for the benefit of a live audience and music that is performed for the purpose of being recorded and distributed through the music retail system or the broadcasting system. However, there are also many cases where a live performance in front of an audience is recorded and distributed (or broadcast).