MPHO RANTAO TRIBUTES have continued to pour in for Sibongile Khumalo, the late South African multi-award winning music superstar who graced stages around the world with megastars.  Khumalo passed away yesterday after she suffered a stroke. Many of her fans took to social media to pay tribute to Khumalo (63), a musician whose voice was used for many occasions including birthdays, weddings and funerals. Her music appealed to different generations and race groups.  Khumalo received lots of praise for her work in opera classics. She was also honoured by the government with the Order of Ikhamanga for her outstanding contribution…