This is an especially poignant image of one of the world's most famous musicians. John Lennon, formerly the driving force behind the Beatles and author of hits like 'Imagine' and 'Working Class Hero,' was considered such a revolutionary force that he was monitored by the FBI for years. They were concerned that he was a Marxist who might radicalize the young people of America! Lennon did want people to think more about how they could make the world a better place, but more than that he wanted to entertain them.
In this picture, Lennon is signing an autograph for Mark Chapman on December 8th, 1980. A few short hours after the photo was taken, Chapman shot him dead. Chapman has never provided any explanation for his crime, and remains incarcerated to this day. Lennon was 40 years old.