John Lewis was born in La Grange, Illinois, and after his parents' divorce moved with his mother, a trained singer, to Albuquerque, New Mexico when he was two months old.

[5] After attending Albuquerque High School,[6] he then studied at the University of New Mexico,[4] where he led a small dance band that he formed[7] and double majored in Anthropology and Music.

[5] His piano teacher at the university was Walter Keller, to whom he paid tribute on the title composition of the Modern Jazz Quartet's 1974 album In Memoriam.

[4] Although his move to New York turned his musical attention more towards jazz, he still frequently played and listened to classical works and composers such as Chopin, Bach and Beethoven.

While in Europe, Lewis received letters from Davis urging him to come back to the United States and collaborate with him, Gil Evans, Gerry Mulligan and others on the second session of Birth of the Cool.

[4] The Modern Jazz Quartet was formed out of the foursome's need for more freedom and complexity than Gillespie's big band, dance-intended sound allowed.

[14] Francis Davis, in his book In the Moment: Jazz in the 1980s, wrote that by "fashioning a group music in which the improvised chorus and all that surrounded it were of equal importance, Lewis performed a feat of magic only a handful of jazz writers, including Duke Ellington and Jelly Roll Morton, had ever pulled off—he reconciled the composer's belief in predetermination with the improviser's yen for free will".

[4] Lewis's compositions were paramount in earning the MJQ a worldwide reputation for managing to make jazz mannered without cutting the swing out of the music.

[26] Gunther Schuller for High Fidelity Magazine wrote: It will not come as a surprise that the Quartet's growth has followed a line parallel to Lewis' own development as a composer.

A study of his compositions from the early "Afternoon in Paris" to such recent pieces as "La Cantatrice" and "Piazza Navona" shows an increasing technical mastery and stylistic broadening.

[27]During the same time period, Lewis held various other positions as well, including head of faculty for the summer sessions held at the Lenox School of Jazz in Lenox, Massachusetts from 1957 to 1960,[4] director of the annual Monterey Jazz Festival in California from 1958 to 1983,[10] and its musical consultant,[28] and "he formed the cooperative big band Orchestra U.S.A., which performed and recorded Third Stream compositions (1962–65)".

[4] Orchestra U.S.A., along with all of Lewis's compositions in general, were very influential in developing "Third Stream" music, which was largely defined by the interweave between classical and jazz traditions.

[32] In 1981, the Modern Jazz Quartet re-formed for a tour of Japan and the United States, although the group did not plan on performing regularly together again.

[32] His teaching style involved making sure the student was fluent in "three basic forms: the blues, a ballad, and a piece that moves".

[5] Lewis, who was significantly influenced by the arranging style and carriage of Count Basie,[44] played with a tone quality that made listeners and critics feel as though every note was deliberate.

This band had some of the greatest jazz soloists exchanging and improvising ideas with and counter to the ensemble and the rhythm section, the whole permeated with the fold-blues element developed to a most exciting degree.

[47] Because of his classical training, in addition to his exposure to bebop, Lewis was able to combine the two disparate musical styles and refine jazz so that there was a "sheathing of bop's pointed anger in exchange for concert hall respectability".

[21] His piano style, bridging the gap between classical, bop, stride and blues, made him so "it was not unusual to hear him mentioned in the same breath with Morton, Ellington, and Monk".

[4] Thomas Owens describes his accompaniment style by noting that "rather than comping—punctuating the melody with irregularly placed chords—he often played simple counter-melodies in octaves which combined with the solo and bass parts to form a polyphonic texture".

[55] His compositions were influenced by 18th-century melodies and harmonies,[4] but also showed an advanced understanding of the "secrets of tension and release, the tenets of dynamic shading and dramatic pause"[53] that was reminiscent of classic arrangements by Basie and Ellington in the early swing era.

[57] High Fidelity magazine wrote that his "works not only show a firm control of the compositional medium, but tackle in a fresh way the complex problem of improvisation with composed frameworks".