What Jean-Michel Basquiat knew—what he paid attention to—frequently surprised me. In 1977, I was in public high school with Jean at the somewhat experimental City-As-School, in Brooklyn. Hanging out with him at his father’s house, I picked up an issue of Newsweek and pointed to a photo of Mikhail Baryshnikov, who was considered, I told him, the world’s greatest male dancer. “I thought it was Nureyev,” Jean said.

Indeed, the street and the conservatory—popular expression and high art—influenced Basquiat equally. At C.A.S., we didn’t have teachers; we had “advisers.” One of them described Basquiat to me in 1988, just after he died. He was “totally permeable,” she said, “open to any stimulations. Almost no skin—it all kind of went through him and then came out.”