Like so many musical innovators, Miles Davis was a blackguard. He consumed galaxies of narcotics, inflicted bizarre mood swings on anyone near him, issued completely contradictory orders to his bandmates, treated women like objects (thereby gaining the devotion of dozens of them, of course) and took shit from no-one, as this gem from the Guardian shows:
Davis was a man of few words. When he did speak, his words often had a similar effect to a hand grenade being lobbed into the room. In 1987, he was invited to a White House dinner by Ronald Reagan. Few of the guests appeared to know who he was. During dinner, Nancy Reagan turned to him and asked what he'd done with his life to merit an invitation. Straight-faced, Davis replied: "Well, I've changed the course of music five or six times. What have you done except fuck the president?"
You have to imagine him saying this in his trademark guttural growl. For more on this reprehensible genius, the Mike Dibb documentary from 2001 is first-rate.