Cool jazz

Cool jazz is a style and genre of modern jazz music inspired by bebop and big band that arose in the United States after World War II. It is characterized by relaxed tempos and a lighter tone than that used in the fast and complex bebop style. Cool jazz often employs formal arrangements and incorporates elements of classical music. Broadly, the genre refers to a number of post-war jazz styles employing a more subdued approach than that of contemporaneous jazz idioms. As Paul Tanner, Maurice Gerow, and David Megill suggest, "the tonal sonorities of these conservative players could be compared to pastel colors, while the solos of [Dizzy] Gillespie and his followers could be compared to fiery red colors."

The term cool started being applied to this music around 1953, when Capitol Records released the album Classics in Jazz: Cool and Quiet. Mark C. Gridley, writing in the All Music Guide to Jazz, identifies four overlapping sub-categories of cool jazz:

Cool jazz emerged as a reaction to bop, and is characterized by more moderate tempos and "a more reflective attitude". Ted Gioia and Lee Konitz have each identified cornetist Bix Beiderbecke and saxophonist Frankie Trumbauer as early progenitors of the cool aesthetic in jazz. Gioia cites Beiderbecke's softening of jazz's strong rhythmic impact in favor of maintaining melodic flow, while also employing complex techniques such as unusual harmonies and whole tone scales. Trumbauer, through "his smooth and seemingly effortless saxophone work," greatly affected tenor saxophonist Lester Young, who prefigured – and influenced – cool jazz more than any other musician.

Young's saxophone playing employed a light sound, in contrast to the "full-bodied" approach of players such as Coleman Hawkins. Young also had a tendency to play behind the beat, instead of driving it. He more strongly emphasized melodic development in his improvisation, rather than "hot" phrases or chord changes. While Young's style initially alienated some observers, the cool school embraced it. (Young would also influence bebop through Charlie Parker's emulation of Young's playing style.) Tanner, Gerow, and Megill point out that "cool developed gradually, as did previous styles." In addition to Lester Young's approach, cool had other antecedents:

Saxophonist Benny Carter underplayed his attacks, Teddy Wilson played the piano with a delicate touch, Benny Goodman stopped using the thick vibrato of Jimmy Noone and other clarinetists. Miles Davis's solo on Charlie Parker's "Chasin' the Bird" in 1947 and John Lewis's piano solo on Dizzie Gillespie's record of "'Round Midnight" in 1948 anticipated the Cool Era.

Cool jazz emerged in the 1940s. Its stylistic origins can be traced to Claude Thornhill's big band, which utilized clarinets, French horns, and tubas.

In 1947, Woody Herman formed a band that included tenor saxophonists Stan Getz, Zoot Sims, and Herbie Steward, and baritone saxophonist Serge Chaloff. The result was the "Four Brothers" sound, in which four strong improvisers could still perform well as a coordinated, blended section. (Jimmy Giuffre composed "Four Brothers", which highlighted this group.) The Herman band's recording of "Early Autumn" launched Getz's career. Meanwhile, between 1946 and 1949, baritone saxophonist and arranger Gerry Mulligan, arranger Gil Evans, and alto saxophonist Lee Konitz were all working for the Claude Thornhill Orchestra, whose instrumentation included a French horn and tuba.

In 1948, Miles Davis formed a nonet including Mulligan, Konitz, and Evans from Thornhill's orchestra. Capitol Records recorded the group (at arranger Pete Rugolo's suggestion) in 1949 and 1950. These recordings, originally issued as 78 rpm records, were later compiled as Birth of the Cool (1957). Gerry Mulligan explained that the idea behind Davis's Nonet was not to get away from bebop, but "just to try to get a good little rehearsal band together. Something to write for.... As far as the 'Cool Jazz' part of it, all of that comes after the fact of what it was designed to be." As for Davis, his concern at the time was simply to play with a lighter sound, which he believed to be more expressive. Also his choice of notes suggested deliberation rather than wild exuberance.