Explain the relationship between the growth of the middle class, the changes in the economy, and the new forms of mass entertainment

As more people move out of poverty and into the middle class, there is more discretionary income, which can be spent on entertainment. Mass entertainment is formed in response to the demands of the middle class, and then provides new industries which then create more jobs, moving more people into the middle class, to create more discretionary income. It's a nice circle
 

Ithink its trade and commernce let me know if im wrong