By 1991, the world’s most celebrated trumpeter could look back on five decades of musical evolution – his own, and that of the world around him. Miles Davis had found ways of marrying jazz with classical ideas, then later R&B, rock and funk, producing hybrid offspring that shaped the course of popular music and had come to define his legend. In 1985, he’d left Columbia after thirty years to sign to Warner Bros. Records, a label riding high with best-selling artists like Madonna, Van Halen and Prince, with whom he had a mutual admiration and friendship.