The always illuminating Chuck D spoke at Berklee College of Music’s Martin Luther King Jr. Celebration Friday. The frontman for the seminal hip-hop group Public Enemy was joined at the event by Wayne Dozier , the grandfather of DJ Henry, the Pace University student from Easton who was killed four years ago by a police officer in New York. Friday’s panel, focused on police brutality, environmental justice, gender equality, and LGBT civil rights, also included Berklee faculty members Matt Jenson, Omar Thomas, and Carolyn Wilkins, and staff member Janicanne Shane.