69 is a phenomena well worth understanding. Gandhi, the director of the new documentary, “69: The Saga of Danny Fernandez,” tells us what he’s learned about the rise and fall of the controversial Bushwick rapper who rode social media and criminal behavior to fame and fortune, only to lose his friends, family and wind up in prison. The film’s director talks about Bushwick, pop, politics and the attention economy; the dangers and seduction of fame; and how his years at Vice News prepared him for his career.