At least in American history, when blacks were oppressed, collective singing became a tradition. Many black people often get together to sing at night. So did the black army during the Civil War. Later, now church tradition is a way to inherit singing ability. In fact, these seemingly musical advantages can be said to be their own unique culture created under the oppression of whites in history. Use this culture to gain social recognition. Motown, a famous music company in 1960s, was founded by blacks themselves in white society. Its establishment and continuation played an important role in the history of music and the development of black music culture. Over time, cultural influence helped a lot. Now it is basically the help of church culture. Children have been influenced by these influences since childhood and found those geniuses from them. In fact, I personally think there are some natural factors in it. But I'm not sure about this for the time being. My girlfriend is black. All the friends around her sing very well. They all sang in church that year.