Jazz is a musical tradition and style of music that originated at the beginning of the 20th century in African American communities in the Southern United States from a confluence of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th century American popular music. Its West African pedigree is evident in its use of blue notes, improvisation, polyrhythms, syncopation, and the swung note.

The word "jazz" (in early years also spelled "jass") began as a West Coast slang term and was first used to refer to music in Chicago in about 1915. From its beginnings in the early 20th century jazz has spawned a variety of subgenres: New Orleans Dixieland dating from the early 1910s, big band-style swing from the 1930s and 1940s, bebop from the mid-1940s, a variety of Latin jazz fusions such as Afro-Cuban and Brazilian jazz, free jazz from the 1950s and 1960s, jazz fusion from the 1970s, acid jazz from the 1980s (which added funk and hip-hop influences), and Nujazz in the 1990s. As the music has spread around the world it has drawn on local, national, and regional musical cultures, its aesthetics being adapted to its varied environments and giving rise to many distinctive styles.

Jazz can be very hard to define because it spans from Ragtime marches to 2000s-era fusion. Attempts have been made to define jazz from the perspective of other musical traditionsusing the point of view of European music history or African music for examplebut jazz critic Joachim Berendt argues that all such attempts are unsatisfactory. One way to get around the definitional problems is to define the term "jazz" more broadly. Berendt defines jazz as a "form of art music which originated in the United States through the confrontation of blacks with European music"; he argues that jazz differs from European music in that jazz has a "special relationship to time, defined as 'swing'", "a spontaneity and vitality of musical production in which improvisation plays a role"; and "sonority and manner of phrasing which mirror the individuality of the performing jazz musician". Travis Jackson has also proposed a broader definition of jazz which is able to encompass all of the radically different eras: he states that it is music that includes qualities such as "swinging", improvising, group interaction, developing an 'individual voice', and being 'open' to different musical possibilities". Krin Gabbard claims that jazz is a construct or category that, while artificial, still is useful to designate a number of musics with enough in common to be understood as part of a coherent tradition. While jazz may be difficult to define, improvisation is clearly one of its key elements. Early blues was commonly structured around a repetitive call-and-response pattern, a common element in the African American oral tradition. A form of folk music which rose 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 sometimes left to the performer's discretion, the performer's primary goal is to play a composition as it was written...