Tyler, the Creator bursts through the service entrance of Jon & Vinny’s, the L.A. restaurant where he asked me to meet him, fixes his eyes on mine and issues a gruff command: “Grab your shit.” Without further explanation, he turns on his heels and vanishes the same way he came. I stammer a goodbye to a confused waiter and hurry into the alley out back, where Tyler’s behind the wheel of a vintage BMW E30 M3 coupe, its engine growling monstrously. He’s wearing black high-water trousers and a white T-shirt decorated with a pixelated flower, both of which he designed for his fashion brand Golf Wang. Our plan was to get a...