George Michael performs the second date of his “25 Live North American Tour” at the HP Pavilion, on June 19, 2008, in San Jose, California Musician Prince speaks onstage at the 55th Annual GRAMMY Awards at Staples Center, on Feb. 10, 2013, in Los Angeles, California Singer David Bowie stands backstage at The Film Society of Lincoln Center’s Tribute to Susan Sarandon at Avery Fisher Hall, May 5, 2003, in New York City. It’s been a tough year for the music industry, which has said goodbye to some of its greatest artists.