Bee Gees singer / songwriter Robin Gibb passed away Sunday after battling several ailments over the last few years.  He was 62.  "The family of Robin Gibb, of the Bee Gees, announce with great sadness that Robin passed away today following his long battle with cancer and intestinal surgery," his spokesperson confirmed in a statement. "The family have asked that their privacy is respected at this very difficult time."  Gibb's twin brother Maurice passed away in 2003, and his brother Barry is the last surviving member of the popular trio.  The Bee Gees are the sixth-biggest selling pop group of all time and have been inducted into the Rock and Roll Hall of Fame and the Songwriters Hall of Fame.