Weeks after the May 4 killing of four unarmed students by The Ohio National Guard at Kent State University, Neil Young wrote this poignant song. Some of the students were protesting President Richard Nixon’s new military campaign in Cambodia during the Vietnam War. Nine other students not involved with the protest were wounded. The song was released as a single by Crosby, Stills, Nash & Young in June. “Four dead in Ohio,” Young sings. — K.B.