Miles Davis in the context of "Fred Plaut"

Jazz improvisation is the spontaneous invention of melodic solo lines or accompaniment parts in a performance of jazz music. It is one of the defining elements of jazz. Improvisation is composing on the spot, when a singer or instrumentalist invents melodies and lines over a chord progression played by rhythm section instruments (piano, guitar, double bass) and accompanied by drums. Although blues, rock, and other genres use improvisation, it is done over relatively simple chord progressions which often remain in one key (or closely related keys using the circle of fifths, such as a song in C Major modulating to G Major).

Jazz improvisation is distinguished from this approach by chordal complexity, often with one or more chord changes per bar, altered chords, extended chords, tritone substitution, unusual chords (e.g., augmented chords), and extensive use of ii–V–I progression, all of which typically move through multiple keys within a single song. However, since the release of Kind of Blue by Miles Davis, jazz improvisation has come to include modal harmony and improvisation over static key centers, while the emergence of free jazz has led to a variety of types of improvisation, such as "free blowing", in which soloists improvise freely and ignore the chord changes.

Kind of Blue is a studio album by American jazz musician Miles Davis, released on August 17, 1959, by Columbia Records. For this album, Davis led a sextet featuring saxophonists John Coltrane and Julian "Cannonball" Adderley, pianist Bill Evans, bassist Paul Chambers, and drummer Jimmy Cobb, with new band pianist Wynton Kelly replacing Evans on "Freddie Freeloader". The album was recorded at Columbia's 30th Street Studio in New York City in two sessions on March 2 and April 22, 1959.

Influenced in part by Evans, who had been a member of the ensemble in 1958 and was called back for this album, Davis departed further from his early hard bop style in favor of greater experimentation with musical modes, as on the title track of his previous album, Milestones (1958). Basing Kind of Blue entirely on modality, Davis gave each performer a set of scales that encompassed the parameters of their improvisation and style and consequently more creative freedom with melodies; Coltrane later expanded on this modal approach in his own solo career.

John Birks "Dizzy" Gillespie (/ɡɪˈlɛspi/ ghih-LES-pee; October 21, 1917 – January 6, 1993) was an American jazz trumpeter, bandleader, composer, educator and singer. He was a trumpet virtuoso and improviser, building on the virtuosic style of Roy Eldridge but adding layers of harmonic and rhythmic complexity previously unheard in jazz. His combination of musicianship, showmanship, and wit made him a leading popularizer of the new music called bebop. His beret and horn-rimmed spectacles, scat singing, bent horn, pouched cheeks, and light-hearted personality have made him an enduring icon.

In the 1940s, Gillespie, with Charlie Parker, became a major figure in the development of bebop and modern jazz. He taught and influenced many other musicians, including trumpeters Miles Davis, Jon Faddis, Fats Navarro, Clifford Brown, Arturo Sandoval, Lee Morgan, Chuck Mangione, and balladeer Johnny Hartman.

Armando Anthony "Chick" Corea (June 12, 1941 – February 9, 2021) was an American jazz pianist, composer, bandleader, and occasional percussionist. His compositions "Spain", "500 Miles High", "La Fiesta", "Armando's Rhumba", and "Windows" are considered jazz standards.

As a member of the Miles Davis band in the late 1960s, Corea participated in the birth of jazz fusion. In the 1970s he formed Return to Forever. Along with McCoy Tyner, Herbie Hancock and Keith Jarrett, Corea is considered one of the foremost pianists of the post-John Coltrane era.

Return to Forever is an American jazz fusion band that was founded by the late pianist Chick Corea in 1972. The band has had many members, with the only consistent bandmate of Corea's being bassist Stanley Clarke. Along with Weather Report, The Headhunters, and Mahavishnu Orchestra, Return to Forever is often cited as one of the core groups of the jazz-fusion movement of the 1970s. Several musicians, including Clarke, Flora Purim, Airto Moreira and Al Di Meola, came to prominence through their performances on Return to Forever albums.

After playing on Miles Davis's jazz-fusion albums In a Silent Way (1969) and Bitches Brew (1970), Corea formed an avant-garde jazz band called Circle with Dave Holland, Anthony Braxton and Barry Altschul. In 1972, after converting to Scientology, Corea decided he wanted to communicate better with his audience. This meant performing a more accessible style of music than avant-garde jazz.

Josef Erich Zawinul (/ˈzɒvɪnəl/ ZOV-in-əl; 7 July 1932 – 11 September 2007) was an Austrian jazz and jazz fusion keyboardist and composer. First coming to prominence with saxophonist Cannonball Adderley, Zawinul went on to play with Miles Davis and to become one of the creators of jazz fusion, a musical genre that combined jazz with rock. He co-founded the groups Weather Report and The Zawinul Syndicate. He pioneered the use of electric piano and synthesizer, and was named "Best Electric Keyboardist" twenty-eight times by the readers of DownBeat magazine.

Anthony Tillmon Williams (December 12, 1945 – February 23, 1997) was an American jazz drummer.Williams first gained fame as a member of Miles Davis' "Second Great Quintet", and later pioneered jazz fusion with Davis' group and his own combo, the Tony Williams Lifetime. In 1970, music critic Robert Christgau described him as "probably the best drummer in the world." Williams was inducted into the Modern Drummer Hall of Fame in 1986 and the Percussive Arts Society Hall of Fame in 1997.

William Henry Marcus Miller Jr. (born June 14, 1959) is an American musician, songwriter, and record producer. He has worked with trumpeter Miles Davis, pianist Herbie Hancock, singer Luther Vandross, and saxophonists Wayne Shorter and David Sanborn, among others. He was the main songwriter and producer on three of Davis's albums: Tutu (1986), Music from Siesta (1987), and Amandla (1989). His collaboration with Vandross was especially close; he co-produced and served as the arranger for most of Vandross's albums, and he and Vandross co-wrote many songs, including the hits "I Really Didn't Mean It", "Any Love", "Power of Love/Love Power" and "Don't Want to Be a Fool". Miller also co-wrote the 1988 single "Da Butt" for Experience Unlimited.

Julian Edwin "Cannonball" Adderley (September 15, 1928 – August 8, 1975) was an American jazz alto saxophonist of the hard bop era of the 1950s and 1960s.

Adderley is perhaps best remembered by the general public for the 1966 soul jazz single "Mercy, Mercy, Mercy", which was written for him by his keyboardist Joe Zawinul and became a major crossover hit on the pop and R&B charts. A cover version by the Buckinghams, who added lyrics, also reached No. 5 on the charts. Adderley worked with Miles Davis, first as a member of the Davis sextet, appearing on the seminal records Milestones (1958) and Kind of Blue (1959), and then on his own 1958 album Somethin' Else. He was the elder brother of jazz trumpeter Nat Adderley, who was a longtime member of his band.