Slaves were forbidden from owning musical instruments as they were used to communicate. Congo Square in New Orleans was the only place slaves were allowed to gather every Sunday, to trade, sing, dance and play music. This led to the birth of Jazz.
In 1919, a serial killer in New Orleans stated he would kill again, but would spare the occupants of any place where a jazz band was playing. On that night, all dance halls reached capacity and amateur bands played jazz at hundreds of house parties. There were no murders.