Many New Orleans musicians, including Armstrong, migrated to Chicago, influencing local musicians and stimulating the evolution of the Chicago style. This style emphasized soloists and usually produced tenser rhythms and more complicated textures. Instrumentalists working in Chicago or influenced by the Chicago style included trombonist Jack Teagarden, banjoist Eddie Condon, drummer Gene Krupa, and clarinettist Benny Goodman. The Harlem district of New York City became the center of a highly technical, hard-driving solo style known as stride piano. The most popular performer of this approach was Fats Waller, a talented vocalist and entertainer as well. A second piano style to develop in the 1920s was boogie-woogie, which consists of a short, sharply accented bass pattern played over and over by the left hand while the right hand plays freely, using a variety of rhythms. The most innovative pianist of the 1920s was Earl "Fatha" Hines, a Chicago-nurtured virtuoso. Also during the 1920s, large groups of jazz musicians began to play together, forming the so-called big bands that became so popular in the 1930s and early 1940s that the period was known as the swing era. Orchestras were divided into instrumental sections, each with its own riffs (short melodic patterns in call-and-response patterns), and opportunities were provided for musicians to play extended solos.
The development of the big band as a jazz medium was largely the achievement of Duke Ellington and Fletcher Henderson. Other bands in the tradition were led by Jimmie Lunceford, Chick Webb, and Cab Calloway. A different style of big-band jazz was developed in Kansas City, Missouri, during the mid-1930s and was epitomized by the band of Count Basie. Basie's tenor saxophonist Lester Young played with a delicate tone and long, flowing melodies, laced with an occasional avant-garde honk or gurgle, opening up a whole new approach. Jazz singing in the 1930s was led by Ivie Anderson, Mildred Bailey, Ella Fitzgerald, and, above all, Billie Holiday. The pre-eminently influential jazz musician of the 1940s was saxophonist Charlie Parker, who became the leader of a new style known as bebop, rebop, or bop. Bebop was still based on the principle of improvisation over a chord progression, but the tempos were faster, the phrases longer and more complex, and the emotional range expanded. Parker's frequent collaborators were trumpeter Dizzy Gillespie, pianist Earl "Bud" Powell, and drummer Max Roach. Also highly regarded were pianist-composer Thelonious Monk, trumpeter Fats Navarro, and singer Sarah Vaughan. The late 1940s brought forth an explosion of experimentation in jazz. The most influential of the mid-century experiments with classically influenced jazz were recordings made by an unusual group of nine musicians led by Charlie Parker's protégé, a young trumpeter named Miles Davis. The written arrangements, by Davis and others, were soft in tone but highly complex. Many groups adopted this so-called cool style, especially on the West Coast, and so it became known as West Coast jazz. Refined by players such as tenor saxophonists Zoot Sims and Stan Getz and baritone saxophonist Gerry Mulligan, cool jazz flourished throughout the 1950s. Most musicians, however, continued to expand on the hotter, more driving bebop tradition. Major exponents of the hard-bop or East Coast style included drummer Art Blakey and tenor saxophonist Sonny Rollins.
In 1959 Davis and pianist Bill Evans devised the landmark Miles Davis album, Kind of Blue, which also featured tenor saxophonist John Coltrane. The album contains a set of songs that remain in one key, chord, and mode for as long as 16 measures at a time which led to the term modal jazz. Also active during the 1950s and 1960s was composer, bassist, and bandleader Charles Mingus, who imbued his chord-progression-based improvisations with a wild, raw excitement.
Most controversial was the work of alto saxophonist Ornette Coleman, whose improvisations, at times almost atonal, did away with chord progressions altogether, while retaining the steady rhythmic swing so characteristic of jazz. Jazz underwent an economic crisis in the late 1960s, as audiences began to favour other types of music. Jazz musicians realized that to regain an audience they would have to draw ideas from popular music, creating a form called fusion jazz. In the mid-1980s there was renewed interest in serious jazz. Associated with this interest was trumpeter Wynton Marsalis, who was also acclaimed for his performances of classical music. Although jazz remained essentially the provenance of American musicians, its international audience flourished to the extent that non-American musicians began to form an increasingly significant subgroup within jazz.
