If I were researching a paper like this, my thesis would be based largely on the idea that slave spirituals had multiple origins. When I say this, I do not mean that they were originated by multiple groups of people (though the individual songs were), but rather that the spiritual as a genre originated due to multiple influences and multiple needs on the part of the slaves. Let us look at what I mean by this.
First, I would say that your thesis should pay some attention to at least two influences that affected the development of slave music. One of these influences was the slaves’ African heritage. Spirituals are believed to have developed in part from the important place that music had in all phases of West African life. When slaves developed the spirituals, they were in some way trying to hold on to the musical traditions of their native (or ancestral) land. The second of the influences was Christianity. Slave spirituals also reflected a deep commitment to Christianity. As slaves started to make new lives for themselves in America, they were exposed to Christianity and eventually came to embrace it. Thus, the spirituals arose out of a fusion between African traditions and Christian theology and stories.
Second, I would say that your thesis should pay attention to the needs that the spirituals fulfilled for the slaves. Here, too, we can look at at least two major needs. The first need, as discussed above, was the need to connect to and deepen their new religious faith. The spirituals were, at root, religious songs. They focused on the aspects of Christianity (things like the idea of deliverance and of justice in the next world) that most appealed to a people who were held in bondage. The second need was the need for resistance. Many spirituals are said to have had an element of resistance. There were “signal songs” that were meant to communicate impending events to other slaves. There were “map songs” that were meant to help teach slaves how to escape. In short, the songs were not just about spirituality, but were also about resisting slavery.
Thus, I would focus my thesis on the multiple origins and meanings of the slave spirituals. I would have a thesis that read something like “As the first form of African American music, the slave spirituals are of great importance to our history. They reflect the synthesis of African and American influences and they reflect the slaves’ attempts both to deepen their religious faith and to resist slavery in this world.”