MUSIC

Music is an art form whose medium is sound. 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 (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.
To many people in many cultures music is an important part of their way of life. Greek philosophers and ancient 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." 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'."

20th and 21st century music:

With 20th century music, there was a vast increase in music listening as the radio gained popularity and phonographs were used to replay and distribute music. The focus of art music was characterized by exploration of new rhythms, styles, and sounds. Igor Stravinsky, Arnold Schoenberg, and John Cage were all influential composers in 20th century art music.
Jazz evolved and became a significant genre of music over the course of the 20th century, and during the second half of that century, rock music did the same. Jazz is an American musical art form which originated in the beginning of the 20th century in African American communities in the Southern United States from a confluence of African and European music traditions. The style's West African pedigree is evident in its use of blue notes, improvisation, polyrhythms, syncopation, and the swung note. From its early development until the present, jazz has also incorporated music from 19th and 20th century American popular music. Jazz has, from its early 20th century inception, spawned a variety of subgenres, ranging from New Orleans Dixieland (1910s) to 1970s and 1980s-era jazz-rock fusion.
Rock music is a genre of popular music that developed in the 1960s from 1950s rock and roll, rockabilly, blues, and country music. The sound of rock often revolves around the electric guitar or acoustic guitar, and it uses a strong back beat laid down by a rhythm section of electric bass guitar, drums, and keyboard instruments such as organ, piano, or, since the 1970s, digital synthesizers. Along with the guitar or keyboards, saxophone and blues-style harmonica are used as soloing instruments. In its "purest form", it "has three chords, a strong, insistent back beat, and a catchy melody." In the late 1960s and early 1970s, rock music branched out into different subgenres, ranging from blues rock and jazz-rock fusion to heavy metal and punk rock, as well as the more classical influenced genre of progressive rock.

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 without premeditation, while rehearsal is vigorous repetition of an idea until it has achieved cohesion. Musicians will sometimes 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.

Music therapy:

Music therapy is an interpersonal process in which the therapist uses music and all of its facets—physical, emotional, mental, social, aesthetic, and spiritual—to help clients to improve or maintain their health. In some instances, the client's needs are addressed directly through music; in others they are addressed through the relationships that develop between the client and therapist. Music therapy is used with individuals of all ages and with a variety of conditions, including: psychiatric disorders, medical problems, physical handicaps, sensory impairments, developmental disabilities, substance abuse, communication disorders, interpersonal problems, and aging. It is also used to: improve learning, build self-esteem, reduce stress, support physical exercise, and facilitate a host of other health-related activities.
One of the earliest mentions of Music Therapy was in Al-Farabi's (c. 872 - 950) treatise Meanings of the Intellect which described the therapeutic effects of music on the soul. Music has long been used to help people deal with their emotions. In the 17th century, the scholar Robert Burton's The Anatomy of Melancholy argued that music and dance were critical in treating mental illness, especially melancholia. He noted that music has an "excellent power ...to expel many other diseases" and he called it "a sovereign remedy against despair and melancholy". He pointed out that in Antiquity, Canus, a Rhodian fiddler, used music to "make a melancholy man merry, ...a lover more enamoured, a religious man more devout." In November 2006, Dr. Michael J. Crawford and his colleagues also found that music therapy helped schizophrenic patients. In the Ottoman Empire, mental illnesses were treated with music.