He may have professed an occasional dislike for the term, but Duke Ellington was and is jazz. His father was a butler and their home life in Washington was comfortable, with the young Edward Kennedy Ellington devoted to his mother. He studied piano from the age of seven and seemed to have an artistic career ahead of him, although it was the ragtime pianists such as Willie 'The Lion' Smith who really took his fancy. He wrote his first tune in 1913 (Soda Fountain Rag, which he played only a handful of times on record) and was playing on the Washington nightlife scene by 1917: 'Duke' came from his habitually seigneurial manner and appearance. Six years later, by now a big man in this milieu, he tried a move to New York. He ended up broke, but tried again later that year and played piano in Elmer Snowden's Washingtonians, which he eventually took over; Sonny Greer, Otto Hardwick and Artie Whetsol were already among the sidemen. The band became a fixture in some of the smaller New York clubs and gradually added more players, but the key arrival was trumpeter Bubber Miley, with his sensational growl techniques.

Ellington first recorded in 1924, but it wasn't until 1926 that he began making records regularly, at first for a host of different labels: East St Louis Toodle-Oo, initially made on 29 November 1926, is perhaps the first characteristic Ellington record. The following year, Duke took his band into The Cotton Club (the engagement which Joe Oliver had turned down), and over the next four years propelled his reputation and orchestra into the front rank of the music. With the arrival of such significant players as Cootie Williams, Johnny Hodges, Harry Carney and Barney Bigard, the Ellington ensemble was now bursting with solo talent, but it was his skill in devising sound-palettes for the orchestra and individual vehicles for his distinctive soloists which set them apart. While at The Cotton Club, a 'jungle' style predominated to fit in with the floor show, with Miley's growl trumpet as the lead voice and Ellington's sly exoticism (exemplified in the likes of Jungle Nights In Harlem, 1927) as a framing device, but after hits such as Mood Indigo (1930) his ambitions widened, and with Creole Rhapsody (1931) he tried his hand at extended composition, the piece first recorded across two sides of a 12-inch 78.

All through the 30s, his creativity seemed limitless: scores of compositions exploited the unique gifts of his players and the confines of the three-minute record. Harry Carney's baritone sax gave the reed section an unrivalled sonority, and the various trumpet sections made light of the fundamental differences between each performer when they all played together. Juan Tizol's valve-trombone, often blended with the reeds rather than the brass, added another individual touch. Although the death of his mother was a very black moment for Ellington (he wrote Reminiscing In Tempo, 1934, as a requiem), most of the decade found him enjoying a scintillating success, which two European tours in 1933 and 1939 added to. When he hired Jimmy Blanton on bass in 1939, it was another turning point: Blanton seemed to modernize the band's rhythms at a stroke. With the further arrival of saxophonist Ben Webster and, as Duke's new compositional right-hand man, Billy Strayhorn, the period 1939–44 glittered with genius, from Strayhorn's tune Take The "A" Train (which became the Ellington theme tune ever after) to such miniature masterpieces as Harlem Air Shaft, Ko Ko, Jack The Bear and countless others: every new record date for Victor seemed to offer fresh riches, and more than any other period of Ellington's music, this is the one scholars agree on as his most consistently inspirational.

Duke began to appear annually at Carnegie Hall, a respectability he hankered after, although the poor reception for another extended work premiered there, Black, Brown And Beige (1943), crushed him. Perhaps that was a turning point: after that, the band's personnel started to shift more often than not. Blanton was dead, Cootie Williams, Ben Webster and others left, and Ellington's compositional zest, while scarcely retarded, seemed to lose some of its invincibility. By 1950 he was becoming seen – as he had surely wished – as a great American composer, even as most of his weekly life was taken up with touring, and playing as many dances as 'concerts'. The long-playing record gave him the chance to explore the extended form as never before, and such works as Liberian Suite, Harlem and the Shakespearean delight Such Sweet Thunder were pieces he seemed to reserve his most concentrated thinking for, although critics complained that the beautiful brevity of the older music was being dispersed, and Ellington never again wrote a popular hit on the level of Satin Doll, Sophisticated Lady or Mood Indigo.

In the rock'n'roll era Ellington had lost much of his popular audience, like all of the swing bandleaders, but an epochal appearance at the 1956 Newport Jazz Festival – with its flag-waving solo by Paul Gonsalves on Diminuendo And Crescendo In Blue – put him back in the headlines and recharged the band's spirit. He never stopped recording, creating a block of otherwise unreleased works which he referred to as 'the stockpile', much of it of the highest quality, and most of it not issued until after his death; but after a long association with RCA in the 30s and 40s, he subsequently made discs for Columbia (1950–62), Capitol (1953–8), Reprise (1962–6 – a ballyhooed signing which disappointingly produced little in the way of great work) and then RCA again (1966–8), with his final recordings emerging on Fantasy and Atlantic. In the 60s he began to be showered with honours – doctorates, fellowships, awards of every kind – which he took in his humorous, gracious stride, while always maintaining the mask behind which most of his feelings were usually hidden: interviewing Ellington, as Michael Parkinson would later discover, never led to a revelation of any kind.

The band was still in great shape during the 60s, with Cootie Williams returning to the fold and latter-day soloists such as Gonsalves and Russell Procope joining the ageless Hodges, and there were magisterial late works such as The Far East Suite (1967), And His Mother Called Him Bill (1967 – a requiem for the recently dead Strayhorn) and New Orleans Suite (1971) to savour. By 1970, though, a picture seemed to be emerging of a man who had somehow outlived his own orchestra: the death of Hodges in 1970 seemed a particularly cruel blow, and Ellington had started to withdraw into religious writing, which was eventually recorded as the three Sacred Concerts. Duke carried on regardless, as if he didn't know of any other way, and with son Mercer as his road manager, he maintained a punishing schedule which was finally closed by his hospitalization with cancer early in 1974.

'The piano player', as he liked to refer to himself in stage announcements, became inimitable: never one to give himself features, he nevertheless provided links, comped, suggested and directed, much as Count Basie did, although with even more flair and with a wider variety of invention. Studio meetings with the likes of John Coltrane and Charles Mingus in the 60s at least gave him some more expansive space as an instrumentalist than he usually allowed with the orchestra. His solo rendition of Strayhorn's Lotus Blossom became his one later indulgence, beautifully realized on the memorial album to his long-serving partner. Strayhorn's work with Ellington is so simpatico that it has been a problem for scholars to figure out who did what in their collaborative work, but 'Monster', as Strayhorn referred to Duke, usually took the credit anyway. He inspired the profoundest loyalty from his men, some of whom – Carney, Hodges, Williams, Gonsalves – stayed with him for decades, even though he would wryly remark that he had 'discovered a gimmick – I give them money'. Whatever his ambitions were as a composer, there is today no more highly regarded figure in American music, and it is the sustained irony of Ellington's life that so much of it was spent in an environment which was considered antithetical to the established cultural hierarchies. The body of work he left behind is so vast – thousands of compositions, tens of thousands of individual recordings in both live and studio conditions – that it is a study which needs a lifetime to comprehend, but the beauty of Ellington's music is that almost any three minutes of it is life-enhancing. Miles Davis's insistence that there should be a day on which every musician gets down on their knees and thanks Duke hardly seems too much of an encomium.

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.