About the "cause and effect rule" of the African American Music 

In a general way, we used to believe that the music is only a cultural thing, we don't think in the deep construction and formation of the music. Each cultural product has their own cause, has, in this way, a group of characteristics that are important to understand the constitution of their structure. The things in the social world, in a academic observation, are not meaningless, the cause and constitution of the social  aspects are not because yes. The thing are by the way that are because there is a reason that supports that. So, the African American Music is a cultural product that response a series of causes and reasons, has their own political and social causes. 
Then, just to make a metaphor, you could imagine the dominoes effect. When you see al the dominoes pieces in the ground, usually, you think how they get there. You can even imagine all the process of the dominoes effect. Cause and effect rule, in the reality the things are not just like that, but is a good way of explain it. 

Now, I do believe that the main cause of the African American Music is the slavery. All the African people had brought to the American territory by the Americans and became the slaves of the American People. That cause started a long and complicate relation between the American people and the African American people. Nowadays, the being of the African American people in the United Estates of America is a very important aspect that is enough to affect the political life either the cultural and social life.

And there were slaves that affect the usual, political, and cultural life of the United States of America. The slaves are a real fact, and it has their own consequences, the slaves, had their own cultural aspects and forms. When they came here they started to act as their culture set like usual. But, the question is that they were not in their original land. The African American people were immigrants, that means that they were in a new land, had been acting and doing  according traditional aspects of their old life and old lands. I mean, they were acting as their traditional folklore set as usual, and were doing cultural things in a new context. That could cause a several effects on the structure of their tradition, and could be the cause of the being of the African American Music.