This was how many famous jazz stars were able to become famous. They played in clubs owned by the Mafia as fronts and then the clubs became popular because the shows were genuinely good.

The Mafia actually engaged in some level of patronage with black jazz performers who otherwise never would’ve been able to be professional musicians. For example, Al Capone’s gang once kidnapped a musician, Fats Waller, to play for his multi-day birthday party, and paid him extremely generously for the performance