According to a research, the jazz musicians unconsciously switch off regions of the brain involved in self-censorship and firing up the area linked to self-expression.  The scientist from the University and the national Institute on Deafness and other communications disorders used FMRI to scan the brains of jazz musicians as they played a specially-designed piano keyboard.

A musical art form which is originally developed by African Americans from around the world since the 20^th century is Jazz. Characterized by blue notes, syncopation, swing, call and response, polyrhythm, and improvisation, also as ht first original art form to emerge from the United States of America, it was described as the “America’s Classical Music”

 “There have long been debates in the jazz community over the definition and the boundaries of “jazz.” In the mid-1930s, New Orleans jazz lovers criticized the “innovations” of the swing era as being contrary to the collective improvisation they saw as essential to “true” jazz. Through the 1940s, ’50s and ’60s, traditional jazz enthusiasts and Bop enthusiasts criticized each other, often arguing that the other style was somehow not “real” jazz. Although alteration or transformation of jazz by new influences has often been initially criticized as a “debasement,” Andrew Gilbert argues that jazz has the “ability to absorb and transform influences” from diverse musical styles^. Commercially-oriented or ‘popular’ music-influenced forms of jazz have both long been criticized, at least since the emergence of Bop. Traditional jazz enthusiasts have dismissed Bop, the 1970s jazz fusion era [and much else] as a period of commercial debasement of the music. However, according to Bruce Johnson, jazz music has always had a “tension between jazz as a commercial music and an art form.””

Source: http://en.wikipedia.org/wiki/Jazz#Jazz_fusion

Latin jazz has two main varieties: Afro-Cuban and Brazilian jazz. Afro-Cuban jazz was played in the U.S. directly after the bebop period, while Brazilian jazz became more popular in the 1960s. Afro-Cuban jazz began as a movement in the mid-1950s as bebop musicians such as Dizzy Gillespie and Billy Taylor started Afro-Cuban bands influenced by such Cuban and Puerto Rican musicians as Xavier Cugat, Tito Puente, and Arturo Sandoval. Brazilian jazz such as bossa nova is derived from samba, with influences from jazz and other 20th century classical and popular music styles. Bossa is generally moderately paced, with melodies sung in Portuguese or English.

In jazz, the skilled performer will interpret a tune in very individual ways, never playing the same composition exactly the same way twice. Depending upon the performer’s mood and personal experience, interactions with fellow musicians, or even members of the audience, a jazz musician/performer may alter melodies, harmonies or time signature at will. European classical music has been said to be a composer’s medium. Jazz, however, is often characterized or described as the product of freethinking creativity, interaction and collaboration, placing equal value on the contributions of composer and performer, skillfully weighing the respective claims of the composer and the improviser.

While jazz may be difficult to define, improvisation is clearly one of its key elements. Early blues was commonly structured and designed around a repetitive call-and-response pattern, a common element in the African American oral tradition. A form of folk music which had emerged in part from work songs and field hollers of rural Blacks, early blues was also highly improvisational. These features are fundamental to the nature of jazz. While in European classical music elements of interpretation, ornamentation and accompaniment are usually remained to the performer’s discretion, the performer’s primary goal is to play a composition as it was written.