Jazz fusion, fusion, or jazz-rock is a musical fusion genre that developed from mixing funk and R&B rhythms and the amplification and electronic effects of rock music, complex time signatures derived from non-Western music and extended, typically instrumental compositions with a jazz approach to lengthy group improvisations, often using wind and brass and displaying a high level of instrumental technique. The term "jazz rock" is often used as a synonym for "jazz fusion" as well as for music performed by late 1960s and 1970s-era rock bands that added jazz elements to their music. Some progressive rock is also labelled "fusion".

After a decade of popularity during the 1970s, fusion expanded its improvisatory and experimental approaches through the 1980s and 1990s. Fusion albums, even those that are made by the same group or artist, may include a variety of styles. Rather than being a codified musical style, fusion can be viewed as a musical tradition or approach.

Herbert Jeffrey "Herbie" Hancock (born April 12, 1940) is an American pianist, keyboardist, bandleader and composer. As part of Miles Davis's Second Great Quintet, Hancock helped to redefine the role of a jazz rhythm section and was one of the primary architects of the "post-bop" sound. He was one of the first jazz musicians to embrace music synthesizers and funk music (characterized by syncopated drum beats). Hancock's music is often melodic and accessible; he has had many songs "cross over" and achieved success among pop audiences. His music embraces elements of funk and soul while adopting freer stylistic elements from jazz. In his jazz improvisation, he possesses a unique creative blend of jazz, blues, and modern classical music, with harmonic stylings much like the styles of Claude Debussy and Maurice Ravel.

Hancock's best-known solo works include "Cantaloupe Island", "Watermelon Man" (later performed by dozens of musicians, including bandleader Mongo Santamaría), "Maiden Voyage", "Chameleon", and the singles "I Thought It Was You" and "Rockit". His 2007 tribute album River: The Joni Letters won the 2008 Grammy Award for Album of the Year, only the second jazz album ever to win the award after Getz/Gilberto in 1965.

Charles Mingus Jr. (April 22, 1922 – January 5, 1979) was an American jazz musician, composer, bandleader, and civil rights activist.

Mingus's compositions retained the hot and soulful feel of hard bop and drew heavily from black gospel music while sometimes drawing on elements of Third stream, free jazz, and classical music. Yet Mingus avoided categorization, forging his own brand of music that fused tradition with unique and unexplored realms of jazz.

Mingus focused on collective improvisation, similar to the old New Orleans jazz parades, paying particular attention to how each band member interacted with the group as a whole. In creating his bands, Mingus looked not only at the skills of the available musicians, but also their personalities. Many musicians passed through his bands and later went on to impressive careers. He recruited talented and sometimes little-known artists whom he assembled into unconventional and revealing configurations. As a performer, Mingus was a pioneer in double bass technique, widely recognized as one of the instrument's most proficient players.

John Mayall, OBE (born 29 November 1933) is an English blues singer, songwriter, and multi-instrumentalist, whose musical career spans over fifty years. In the 1960s, he was the founder of John Mayall & the Bluesbreakers, a band which has included Eric Clapton, Jack Bruce, Peter Green, John McVie, Mick Fleetwood, Mick Taylor, Don "Sugarcane" Harris, Harvey Mandel, Larry Taylor, Aynsley Dunbar, Hughie Flint, Jon Hiseman, Dick Heckstall-Smith, Andy Fraser, Johnny Almond, Walter Trout, Coco Montoya and Buddy Whittington.

Mayall's father was Murray Mayall, a guitarist and jazz music enthusiast. From an early age, John was drawn to the sounds of American blues players such as Leadbelly, Albert Ammons, Pinetop Smith, and Eddie Lang, and taught himself to play the piano, guitars, and harmonica.

Mayall spent three years in Korea for national service and, during a period of leave, he bought his first electric guitar. Back in Manchester, he enrolled at Manchester College of Art (now part of Manchester Metropolitan University) and started playing with semi-professional bands. After graduation, he obtained a job as an art designer but continued to play with local musicians. In 1963, he opted for a full time musical career and moved to London. His previous craft would be put to good use in the designing of covers for many of his coming albums.