Hancock studied piano from an early age, and was a classical prodigy in his home town of Chicago, playing Bach and Mozart on concert platforms when barely into his teens. At college he majored in electrical engineering (which would come in useful later) and composition, but when he went to New York in 1961 it was as a jazz player, with Donald Byrd's group: Blue Note's Alfred Lion was impressed enough by his playing on a Byrd album session to offer him his own date, and Takin' Off (1962) spawned an immediate jazz hit in the infernally catchy original Watermelon Man. By 1963 Hancock was clearly hot property in New York, and Miles Davis enlisted him for his new quintet (at the 'audition' Davis asked Hancock to play a ballad: at its conclusion, he merely said, 'Nice touch'). His five years with Davis were Hancock's golden period of creativity. He fitted in handsomely with Davis's pre-electric music of this era, comping behind soloists with a glittering, literate ease (Hancock once suggested himself that he preferred to accompany rather than solo), interacting smartly with Ron Carter and Tony Williams, and lifting notes off the keyboard with a lustrous, rhapsodic tone which suggested his classical finesse imbued with a knowing sense of blues and bop grammar. While he contributed less to the Davis book than Wayne Shorter did, his own composing continued to blossom on his own-name recordings, for Blue Note and subsequently Warners: Maiden Voyage, Dolphin Dance and Speak Like A Child sounded like instant standards, and Hancock has never again approached the casual mastery of this writing. Empyrean Isles (1964) and Maiden Voyage (1965) evoke a jazz-pastoral idiom which few others – Hancock included – have approached in quite the same way since. It is certainly the Hancock of this period which has been such a powerful influence on modern jazz piano. He wrote the score for Blow Up (1966), although his subsequent adventures in soundtrack music, including the awful Death Wish, were less distinguished.

Affected by the winds of change Davis was manipulating, Hancock also sought the fresh fields of electric music at the end of the decade. His sextet music of 1969–71 was lively, often juicily 'ethnic' long before that flavour became fashionable, and bolstered by the grand jazz chops of such sidemen as Johnny Coles and Joe Henderson; but Hancock's own piano was being steadily supplanted by synths and clavinets and the like, and by the time of Headhunters (1973) the leader had gone over to jazz-funk, which was at least a variation on the jazz-rock most of the competition were trying. That record and band became a benchmark in his career, and it was one he spent the rest of the decade trying to duplicate, with decreasing returns. By the early 80s he was going pop with a shameless enthusiasm, typified by the baby-soft Lite Me Up (1982), yet at the same time he was hedging his bets by playing acoustic, straight-ahead gigs and recording with Chick Corea, Wynton Marsalis and the VSOP supergroup. His hit single Rockit (1983) was seen as revolutionary by some, although now it sounds more like an instrumental novelty: either way, it was his last appearance in the pop charts. Since then, Hancock has chased success on several fronts. He still plays in nostalgic line-ups such as the 1992 Tribute To Miles band, and in an occasional (acoustic) duo with Wayne Shorter. His The New Standard (1995) put up an all-star group to tackle a bunch of rock tunes by the likes of Peter Gabriel and Don Henley: his record company's idea, it lasted one album and one tour. A re-formed Headhunters project worked out much the same two years later. Hancock holds on to a huge following among a certain part of the jazz audience: the Us3 hit 'remix' Cantaloop (based on Canteloupe Island from Empyrean Isles) kept him current among listeners who still think Miles Davis and his various sidemen were the only people who mattered in modern jazz. But there is relatively little among the ponderous and jumbled discography of the past 25 years which really stands up to much scrutiny. A shrewd man with an enormous ego, in his middle 60s Hancock seems to be casting around for something useful to play, although his eminence is surely pretty safe.

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.