Singing practices don't divide up along ethnic or regional lines anywhere. Every culture has multiple performance practices: people don't sing in the bath the same way they do at a football match, in church, at a karaoke night or on a bus when inspired by their mobile phone. Even in church there are different practices within the same ceremony; some bits of liturgy are performed communally, others left as solos for the grand hoodoo in charge.

Code-shifting is something humans are good at.