Long before Sean "Diddy" Combs' history of abuse came to light, alarm bells rang whenever Mark Ronson found himself around the now-disgraced hip-hop mogul. "For all the gigs I played for Puff, he probably spoke five sentences to me. But even to me, the DJ, he emitted a chaotic energy that left me both starstruck and deeply unnerved," Ronson writes in his new memoir, Night People: How to Be a DJ in '90s New York City (out Tuesday, September 16), using Diddy's former stage name Puff Daddy.