Jazz is an American style of music that reflects Americans' roots in Africa and Europe. The style originated in New Orleans during the early years of the 20th century.It combines African-American music, ragtime, and the blues. Jazz is typified by complex collective musical improvisation, syncopation, use of blue notes, and call and response. The first jazz recording was made in 1917 by the Original Dixieland Jazz Band, who drew heavily on African-American influences, as well as the brass bands that were popular in the South at the time.
Up until the mid-to-late 20s, jazz was a polyphonic (or perhaps more accurately, a heterophonic) music - typically, in a band such as King Oliver's, the cornet would hold the main melody, whilst the clarinet would improvise obbligati above and the trombone would add a tenor line below. Gradually, a more solo-oriented style emerged, typified by the Hot Five recordings of Louis Armstrong, where instruments would take turns to solo.
At this time, black and white bands were comprehensively segregated, with the influence of the ODJB hanging heavy over the white bands.
Towards the end of the 1920, the big band sound started to emerge in two places, New York and Kansas City. In New York, the Broadway influence led to the development of sophisticated orchestras such as those of Fletcher Henderson or Duke Ellington, whilst in the Southwest, an earthier, bluesier style was developed by such leaders as Bennie Moten and Jesse Stone.
The early 1930s were something of a lean time for jazz commercially, although fine recordings were being produced by Harlem bandleaders such as Ellington and Cab Calloway. By around 1935 the swing style was being popularised by white bandleaders such as Benny Goodman, (although black bandleaders such as Count Basie, Jimmie Lunceford and Chick Webb had developed it) and by the end of the decade effectively became the sound of Western pop music.
In reaction against the perceived commercialism of swing, and its appropriation by white musicians, a group of young, dedicated musicians sought to create a style deliberately intended to alienate the casual listener. With its complex harmonies and irregular melodies, the bebop style was treated with suspicion by older musicians. Bebop was popular with jazz critics but never achieved mainstream success.
During the 1950s the small group came to dominate mainstream jazz, assuming the form that survives to this day - a rhythm section of piano (playing sparse left hand), double bass and drums, with a front line generally consisting of 'horns' (ie, trumpets and/or saxophones).
Various movements emerged in the 1950s.
Hard bop (epitomised by Horace Silver and Art Blakey brought a 'funky', bluesy feel to the music, in reaction to the complexities of bebop.
Soul jazz, led by artists such as organist Jimmy Smith, combined elements of bebop, R&B, and gospel to create a "soulful" jazz sound.
Modal Jazz (pioneered by theorist George Russell and trumpeter Miles Davis) was also a contrast to bebop, but sought to give the soloists ample space for expression by eliminating frequent chord changes.
As rock became the dominant force in popular music in the 1960s, some jazz musicians decided to adapt to it, with varying degrees of success. Miles Davis' Bitches Brew and Herbie Hancock's Headhunters are two seminal fusion albums.
Courses in jazz are offered at many major schools, with the most notable programs belonging to Berklee College of Music and the University of North Texas (whose "One o'Clock Lab Band" has been nominated for several Grammys), and the number and standard of jazz musicians now is extremely high. Many high schools in the United States today also have jazz bands. A far remove from its New Orleans underclass roots, jazz is a thoroughly mainstream and respected art form.
There are some who believe jazz music to be a negative influence. For this reason, Bob Jones University has banned it, along with New Age, Rock, Country, and Contemporary Christian music, from its dormitories. 
Types of jazz include:
Some jazz musicians include:
- Charlie Parker
- Miles Davis
- Louis Armstrong
- Chet Baker
- Clifford Brown
- Sonny Rollins
- Duke Ellington
- Count Basie
- Dizzy Gillespie
- Maynard Ferguson
- John Coltrane
- Dave Brubeck
- Albert Ayler
- Roy Haynes