Michael Jackson was an American singer, dancer, and entertainer who became the most successful pop artist of all time. Some of his most famous albums included Thriller, which is the best-selling album of all time, and Bad. He helped break down racial barriers in popular music and his music videos for songs like "Billie Jean" and "Thriller" transformed the music video into an art form. In 2009, Jackson was preparing for a major series of comeback concerts in London but died of cardiac arrest at his home at age 50, just weeks before the shows were set to begin. His memorial service was watched by over a billion people worldwide.