I prefer Jypson Butukondolo with this style of chorus singing.
I thought you said he was the weak link at QL?
where solo vocals are concerned he was a weak link in the line up of Quatier Latin, his voice is good for choruses just like Rio's however he still did some good songs for instance Moprete Lendila and Biblia are excellent songs and his solo album Diagnostic has some excellent songs too with him being the lead vocalist throughout.
The worst singers to have gone through Quartier Latin are Shella Mputu and Savanet Depitsho, those two are average singers but again you find that they have done some good vocals on some songs too.
