Jazz-rock fusion is a stream of styles which emerge during the late 1960s. It became the most popular jazz for the next thirty years and the first to have widespread popularity after the swing era.
Jazz, Rock, and funk music share similar roots in gospel music, work songs, and the blues. But they represent the products of two different lines of musical evolution. For example, jazz employs aspects of formal European concert music and steers away from vocals. It is primarily instrumental music that is almost as complicated as twentieth-century symphonic music. Rock and funk music, on the other hand, emphasize vocals and stick largely to simple compositional forms such as the four-chord, twelve-bar blues and other brief chord progression that repeat continuously.
Rock and funk music became a main stream in popular music. Jazz, meanwhile, attracted only a small and specialized audience. While it is true that blues singers from the first part of the twentieth century are routinely cited in jazz history texts, they are usually mentioned in discussions of the origins of jazz rather than the dominant course of jazz itself. The stream of evolving styles that runs from the earliest blues singers through B.B. King to Jimi Hendrix was already essentially separate from jazz by the 1920s.
Prior to the 1950s, blues and gospel music performed by black performers were popular with black audiences. Ranging from Bessie Smith in the 1920s to Louis Jordan in the 40s, these performers made music which marketers called "race records." In 1949, this category acquired a new name: rhythm and blues (R&B). From that time on, it strongly influenced another style of popular music called rock and roll. Besides its R7B roots, much rock also reflects the predominantly white musical stream of country music. Rock is distinctly separate from jazz, further removed than R&B. Note. However, that despite differences in racial and ethnic origins, rock and R&B remain similar because they all use extremely simple melody lines, repeated bass patterns, very steady tempo, and singers as well as instrumentalists who bend the pitches of their notes extensively in a highly stylized manner.
By the mid-1960s, the dominant jazz and rock styles had evolved into uniquely separate idioms with little in common. Then, during the late 1960s, a partial blending of the soul-funk stream and the jazz stream occurred and was labeled "jazz-rock fusion." Some jazz musicians were not affected by funk, and many funk groups were not affected by jazz. But much of the jazz played during the 1970s and 80s was heavily influenced by funk, and some funk groups incorporated more of the improvisation and advanced harmonies found in jazz.
Jazz-rock fusion mixed jazz improvisation with the instrumentation and rhythms of R&B. This mixture was very popular, both with young musicians coming up and with older established players. Rhythm section changed instrumentation by replacing piano with electric piano and synthesizer and by replacing acoustic bass viol ("string bass") with electric bass guitar ("Fender"). Pianists and guitarists often adopted repeating accompanying riffs in place of the spontaneous comping which had been customary since the 1940s. Bassists began collecting the strongly rhythmic, syncopated and staccato bass patterns in the style of James Brown and Motown funk bands of late 1960s and the back-up groups for SlyStone of the early 1970s. Just as some swing era bassists had to switch from brass bass (tuba) to string bass, early fusion bassists often had to switch from string bass ('acoustic") to bass guitar ("electric" or "Fender").
Drummers learned new timekeeping patterns which resembled those of R&B as well as Latin American styled. Jazz-rock drumming style was very full and active. There was more emphasis on the bass drum, and less on cymbals for timekeeping. The rhythms were stated insistently and repeatedly, and not in the more subtle, highly varied manner of jazz. The jazz-rock style maintained a high level of tension for long periods. There was considerably less bounce and lilt than in jazz of the 1950s, and timekeeping was more strictly stated than during the exploratory years of jazz in the 1960s.