It was no longer a social instrument. It was now a performance (instrument) by clowns in blackface performing a very racist stage show to a seated audience.
There are some people who doubt the African origin of the banjo. But even a cursory look at these instruments kind of puts to bed any doubt.
It is arguably the most influential joining of cultures ever.
When it was taken out of the hands of African-Americans and put into the hands of racist white performers, the music and the instrument specifically took on a completely different form and behaved in a completely different function.
