Sibongiseni was born in Ladysmith (eMnambithi district) to Joseph and his wife Nellie, just shortly after the release of the group's first album Amabutho. In 1976, Joseph brought together his six sons to form Mshengu White Mambazo, Ladysmith's 'junior choir'.
After the murder of his uncle Headman Shabalala in December 1991 and the retirement of several other members (Inos Phungula, Geophrey Mdletshe and Ben Shabalala), Joseph later recruited Sibongiseni and his brothers Thamsanqa, Thulani and Msizi. Sibongiseni began singing with Mambazo as a bass voice and has remained in the line-up since 1993.