Few musicians have managed to change the course of music--trumpeter Miles Davis did it several times. An early disciple of Charlie Parker, Davis created an austere, understated approach that became the model for cool. His superb albums in the 1950s made him a star, and in the following decade, he brought small-group jazz to the limit before he unapologetically (and, for some, unforgivably) took on jazz-rock. After a break, he re-emerged in the '80s with a mixture of pop and dense, bristling funk. All the while, his refusal to follow anyone but his own muse made him both a hero and an enigma--either way, he was one of the most magnetic, influential figures in American music.