Michael Jackson passed away unexpectedly last Thursday; he was 50. In the last week, there has been a great surge in radio airplay of his songs, as people paid tribute to the King of Pop. Many public figures in the entertainment industry have come out to express their shock and sorrow over his death — Madonna, Yoko Ono, his ex-wife Lisa Marie Presley, and many others. Some of them knew him personally and others didn’t.