HIDDEN UP A WOODED hill in the sprawling backyard of his suburban Los Angeles estate, Dijon “Mustard” McFarlane is on the tennis court, perfecting his forehand.
“I’m an extremist,” the 34-year-old producer explains as he warms up his top spin. “I play every day, sometimes two times a day.” The L.A.-born musician, who shot to prominence at 21 when he produced Tyga’s 2011 hit “Rack City,” beckons his coach to serve again. After some rallying, Mustard slices a ball that nearly hits the Billboard cameraman kneeling beneath him, trying to get a close-up shot. “Oh, sorry! Man, you’re brave for sitting there,” Mustard says.
“I play, too; it’s cool,” the photographer replies, unfazed.
“Aight, you’re one of us,” Mustard says with a grin, pointing at the man with his…