Davis set countless questions and dilemmas for listeners, musicians and commentators in a monumental and unprecedented body of work. With a personality which vacillated continuously between devil and angel – he must have enjoyed the sobriquet 'Prince Of Darkness', even though any reference to race, however harmlessly meant, drove him to fury – the emotional tenor of his music is all but impossible to read. But he left a mouthwatering, jostling oeuvre, even though masterpieces sometimes rub shoulders with mere spacefillers. His father was a dentist and the young Davis grew up in a middle-class environment in East St Louis. He took up trumpet at 13 and had some useful early advice from Clark Terry, who advised him to forget about using a vibrato – 'You'll get old and start shaking anyway'. When the Billy Eckstine band visited St Louis he sat in, and he went to New York in 1945, determined to make friends with Charlie Parker. He succeeded, but he didn't work formally with him until April 1947; in between he was with Benny Carter, Eckstine and Dizzy Gillespie.

Davis was in Parker's quintet until December 1948 and is the trumpeter on most of the saxophonist's key sessions for Savoy and Dial. While his playing has often been criticized as the weak link on these recordings, it's fairer to say that he was already working towards an altered state in the bebop language: unequipped to be the kind of virtuoso which Gillespie or Fats Navarro were, he stepped cautiously within the middle register of the horn, repeated figures which he liked while subtly varying their placement, and generally bided his time, content to let Bird take the lead. At the same time, he began rehearsing with other musicians of similar temperament, including Gil Evans and Gerry Mulligan, and these sessions led to a small group of 1949–50 nonet recordings which, when first released in a 12-inch LP format, were named Birth Of The Cool (though this wasn't until 1956). The nonet made a few public appearances but didn't find much work, and after a visit to Paris to play with Tadd Dameron, Davis returned to New York and started using heroin, an addiction which badly impeded his progress.

Records for Blue Note and Prestige were at first nothing too special, but in 1954 – when he reportedly overcame his addiction – Davis began to hit his stride. A headline-making appearance at the 1955 Newport Festival put him in the forefront, and with the formation of a fresh quintet (John Coltrane, Red Garland, Paul Chambers, Philly Joe Jones), the sudden demise of Charlie Parker that same year, and the first in a sequence of dazzling records for Prestige by the new band, Davis was set fair to be jazz's premier leader. The quintet's entire output was set down at only a few recording sessions, but the impact of that group – the trumpeter growing ever more concise as a counter to Coltrane's huge outpourings, while the rhythm section set up a feline interplay behind them – rocked a new generation of jazz listeners, and seemed to set the first great standard for the music in the LP era. Davis had also begun using the Harmon mute, which gave his sound a uniquely wounded timbre on ballads in particular. There were some fluctuations in the personnel, in part owing to all four of the sidemen being addicts themselves: at one time Davis had both Coltrane and Sonny Rollins together in the band ('And I have no tapes of that band, damn!').

A larynx operation in 1956 led to Davis spoiling his voice by shouting before his throat had recovered: ever after, he spoke in a cracked whisper. A year later he began the first of several projects where Gil Evans orchestrated backgrounds for Davis as soloist: Miles Ahead (1957), Porgy And Bess (1958) and Sketches Of Spain (1959) were the results, and despite Davis sometimes turning into a preening soliloquist in the gorgeous settings, much of the music is astoundingly beautiful. After a visit to Paris, where he recorded the music for Louis Malle's Ascenseur pour l'échafaud, Davis was back in New York and extending the small group to a sextet, with Cannonball Adderley and, briefly, Bill Evans. Tiring of the way bop-orientated material had gone and complaining that the music had become too thick with chords, Davis sought a fresh direction, which led to the so-called modal playing crystallized in his best-known session, Kind Of Blue, surely the most famous jazz record of the LP era. Abandoning a strict timetable of chords, his group edged towards melody as the directing element, with scales and modes, and rhythmic vamps and drones, folding together to create an allusive new feel which felt elliptical and just mysterious enough to captivate even uncommitted audiences. Davis was by now on Columbia, where he would stay for most of his career, and loved the limelight he was enjoying, although there was the occasional sharp reminder that the world hadn't yet changed that much: in August 1959 he was clubbed by a policeman while innocuously standing outside the Village Vanguard.

After the departure of both Adderley and Coleman, though, Davis's group went through a state of flux: he tried several different saxophonists, from Sonny Stitt to Sam Rivers, and didn't seem to care too much for any of them. In 1963, though, the new backdrop he sought finally fell into place, with the recruitment of Herbie Hancock, Ron Carter and the improbably youthful Tony Williams. While Coltrane was achieving stardom by himself, Davis had seemed to tread water since Kind Of Blue, but Wayne Shorter's arrival to complete the line-up in 1964 drove the music forward: after a period when Davis had explored the same small group of works over and over, Shorter's writing expanded Davis's book and moved towards a further abstraction, his idiosyncratic melodies suiting his leader's taste for ambiguity. Meanwhile, the rhythm section broke further away from the simplicity of 4/4, Williams in particular devising endless rhythmical variations and subtleties without any lessening of power and momentum. A week's work at The Plugged Nickel in 1965 was recorded, and remains a daringly revealing document of one group's collective creativity.

By 1968, though, Davis began to turn away from acoustic music: the Olympian achievements of the quintet must have seemed impossible to sustain, and in any case the leader was tempted by the popular audience won by Jimi Hendrix. In A Silent Way (1969) and Bitches Brew (1970) unveiled the new, electric Miles: recruiting young players such as Joe Zawinul, John McLaughlin, Chick Corea and Jack DeJohnette, Davis dived into a fusion of jazz improvisation with what sounded like rock rhythm and viscerality, although it was inevitably a more sophisticated alliance than that. For five years he was prolific as never before, going into the studio more often than ever, and leading groups at such rock-orientated venues as Fillmore West, the once dapper figure now bedecked in all the extravagant robes of rock fashion. It attracted new fans and repelled many older ones, but it was all signature Miles. After the Japanese live recordings of the remarkable Agharta (1974), though, the trumpeter's health was again suffering: a likely sickle-cell anaemia condition, plus the effects of a car accident, drove him into semi-retirement, and for the rest of the 70s he did little (Eric Nisenson's depressing memoir outlines some of the habits he got into during this time). But by 1981 he was touring again. Much of the darkness of the 70s music had evaporated, and Davis took to covering recent pop material, including Cyndi Lauper's Time After Time and Michael Jackson's Human Nature, which he played over and over, just as he once did with Bye Bye Blackbird. His bands were again filled with young players, including Darryl Jones and a succession of guitarists and saxophonists; the bassist Marcus Miller produced many of his later records, and drummer Al Foster, perhaps his closest latter-day colleague, was on most of them, although a few late waves in the direction of rap and hip-hop suggested that even Miles Davis couldn't adapt to every trend in youth music. There were still many great concerts ahead, and the occasional interesting byway: a Gil Evans-like piece, Aura, was scored for him in 1985 by Palle Mikkelborg, and not long before his death he played some of the old Evans orchestrations at a 1991 Montreux Festival show with Quincy Jones. By this time, though, he was clearly ailing, and he died the following year.

'I have to change,' he once said, 'it's like a curse.' This aspect of Davis's art has always been overplayed by his many biographers and followers. Davis certainly went through far more stylistic ground than most, but he was exceptionally shrewd in his choice of collaborators, and it would be wrong to ignore or undervalue the role of such as John Coltrane, Bill Evans, Gil Evans, Wayne Shorter and Joe Zawinul in the development of his many 'innovations'; nor should the role of Teo Macero, his record producer of many years' standing, be overlooked, particularly in regard to the Bitches Brew era of recordings: Macero appeared to be the only one who made sense of the hours of wayward noodling which went into such records. As a composer, Davis is similarly hard to evaluate: major pieces with his name on them, such as Tune Up, Four, Blue In Green and Solar, are known to be by other hands, and he increasingly relied on the likes of Shorter in later years to come up with most of the basic material for his music. Perhaps his two great gifts were his ability to lead and focus groups thick with talent but lacking a collective persona; and his charisma as a soloist, employing an uncanny knack of turning a musical situation in the direction he chose and using his own instrumental voice to personify it. As an icon, both in the music and at the high end of popular culture, he has no jazz rivals: even Armstrong and Ellington have to bow to him in that regard. Consumed by the corrosive consequences of racism, which obsessed him, and drugs, which shadowed him for most of his adult life, he could be a despicable character, even to friends and lovers; yet he was equally beloved by most of those who knew him. Either way, he left his audience an incomparable legacy.

Biography from Richard Cook's Jazz Encyclopedia (2005).

If you'd like more information, check out The New Grove Dictionary of Jazz (2002) or The Biographical Encyclopedia of Jazz (2007), both of which are still in print.