"I was always enthusiastic about making records with Miles," said Cobb, who got to the studio before the other musicians to set up his drum kit. "I wasn't told anything about what the music was going to be."

Cobb ended up being part of the all-star sextet, plus one, that recorded Kind of Blue, an album Quincy Jones (and many others) consider to be "one of the greatest records ever made".

Since its August 1959 release, Kind of Blue has ranked as one of the most influential and popular jazz albums ever with more than four million copies sold in the US alone, according to the Recording Industry Association of America - and has recently been reissued in deluxe box sets to mark its 50th anniversary.

But in 1959, Cobb - the last surviving musician in a group that included saxophonists John Coltrane and Julian 'Cannonball' Adderley, pianists Bill Evans and Wynton Kelly, and bassist Paul Chambers - regarded it "as just another Miles Davis record date".

"It was relaxed and the guys always had fun around each other," said Cobb. "It had to be the talent, the music, the studio ... I don't know how that magic happens but it happened those two days."

Jones, who as a young trumpeter in the '50s was heavily influenced by his close friend Davis, considers Kind of Blue a culmination of a golden era in jazz that began in the late '40s with the bebop revolution launched by Charlie Parker and Dizzy Gillespie. At the same time, the album foretold the new sounds that would emerge in the '60s.

"It's a record that sounds like it was made yesterday. It's as hip as anything on the planet," said Jones. "It's the accumulation of everything that ... modern jazz is about.

"I have given away hundreds of copies to kids all over the world and said, 'I want you to treat this like orange juice, listening to it every morning'."

The original album (only 37 minutes) has had a huge impact that extended beyond jazz to other genres - from rock musicians such as the Allman Brothers and Carlos Santana to minimalist composers like Steve Reich and Philip Glass.

"Miles' genius was that he was able to keep the quality of the creativity very high and at the same time make a work of art that communicated broadly," said pianist Chick Corea.

Cobb said the musicians struck a groove on the first track they recorded, Freddie Freeloader, a jaunty blues number that was the only tune to feature the more upbeat pianist Kelly.

mistake

Then with the introspective Evans at the piano, the sextet recorded So What, which would become the album's opener, starting with an ethereal bass-and-piano prelude. Cobb hit a cymbal crash just as Davis began his solo, and waited for the trumpeter to call for another take.

"I thought I had made a mistake and had hit the cymbal too hard ... but it worked out because it resonated and got smaller and smaller."

Davis kept the tape rolling, and launched into one of the most memorable solos in jazz history - lyrical and restrained, using space to build drama, with his trumpet having a heartbreaking quality.

"I always loved Miles' trumpet because it sounded soulful. He could get into you with his beautiful, pure sound," said the 80-year-old Cobb, interviewed over lunch at a restaurant on Manhattan's Upper West Side.

"He was trying to create a mood and he did that. ... I heard a lot of people say that probably a lot of babies were made off of that music playing in the background."

Today, the five tunes on Kind of Blue - particularly So What and All Blues - have become deeply embedded in the musical landscape. At the March 2 and April 22, 1959, recording sessions, nearly all the tunes were new to the band members, who didn't even have a chance to rehearse them. Davis gave the musicians written sketches of the scales and melodies, offering brief verbal instructions about the feeling he wanted on a particular tune.

Davis was moving away from bebop with its complex harmonies and improvisations structured around chord changes. The trumpeter asked his musicians to play in a modal style - a concept developed by pianist-composer George Russell - in which the musicians improvised on scales, with the soloists having more freedom to explore long melodic lines.

Though Davis took credit for all the tunes on Kind of Blue, it's now acknowledged that Evans had a significant role in sketching out the ballad, Blue in Green, and the most distinctly modal composition, Flamenco Sketches.

Corea says that "personality-wise they were opposites." Miles was the cool hipster with his designer suits, Italian sports cars and glamorous women. The withdrawn and bespectacled Evans had the rumpled look of a nerdy college professor but both shared a passion for modern classical composers, a penchant for introspective spacious music with an emphasis on lyricism, and a willingness to experiment.

"Miles could see that there was something new that he could do with this guy who was making new sounds on the piano," said Corea, who a decade after Kind of Blue played in Davis' band that recorded the groundbreaking electric jazz-rock fusion album Bitches Brew. "He inspired Miles to another level."

"Miles always had this wonderful characteristic of gravitating towards a creative musician and then having the intelligence to know how to utilise that musician within his own sphere without cramping the guy's style."

soul jazz

That held true for the other musicians who would soon make their own distinctive mark on the jazz scene. Adderley, the jovial, earthy alto saxophonist, would create his own brand of 'soul jazz'. The spiritually searching tenor saxophonist Coltrane was just weeks away from recording his breakthrough album, Giant Steps, with its complex chord progressions and sheets of sound that would set him on a course of bold experimentation. Cobb and Chambers, both of whom played on Giant Steps, formed one of the most in-demand rhythm sections with pianist Kelly.

It wasn't the musicians alone who shaped the album's mood. Columbia's studio in a cavernous abandoned Greek Orthodox church with wood panelling enabled a pure acoustic sound. Cobb said sound engineer Fred Plaut knew exactly where to place each instrument and microphone to capture the slightest nuances.

"There's a lot of great performances in jazz, but the sound may not be that great," said trumpeter Wynton Marsalis. "This is a really good sounding recording. It's simple and it's complex."

After the second recording session, Cobb said the musicians felt they had succeeded in doing "what Miles wanted to do," but nobody had any inkling of the album's enduring legacy.

Davis, who always insisted that he didn't want to look back, never tried to capture the album's mood when he'd perform So What and All Blues with his second great quintet of the mid-'60s that included pianist Herbie Hancock and saxophonist Wayne Shorter.

"We'd play them three times as fast," said bassist Ron Carter, who joined Davis' band in 1963. "I was always asking Miles why is this so fast tonight, what happened to the medium tempo from the record. He would say to me, 'I just hear it faster now'."

By the end of the '60s, Davis had stopped playing any Kind of Blue tunes. The music continues to be covered not only by former Davis sidemen like Hancock and Carter, but numerous other jazz musicians. Cobb is marking the 50th anniversary by performing the complete album on tour with his So What Band, including trumpeter Wallace Roney, whom Davis selected to perform with him at a 1991 concert in Montreux, Switzerland, two months before his death.

Trumpeter Chris Botti says he was drawn to Kind of Blue as a high school student in Oregon in the '70s, and features Flamenco Sketches in his repertoire, including it on his latest CD/DVD, In Boston.

"It's a jazz song but the chords are just so open ... and it's incredibly satisfying to play," said Botti.

"Jazz musicians are never known for their restraint and this record is perfect in its restraint. I believe this record is more of a pop album than a jazz album. Miles didn't have a hit song, he had a hit mood."