Apiece of music played as an introduction to the main piece is called a

The correct answer is - overture.

The overture, also commonly known as intro, is the piece of music that is played as an introduction to the main piece. It is the one that starts the show. This piece of music can range a lot in length, though most commonly it is short, around one to one and a half minutes.

It is a specifically made piece of music that has a purpose of introducing the listeners to what they can expect, but it is a short piece that manages to incorporate the vibe, the feelings, the theme, of what will come.

The correct answer is A. Christians.

Explanation

In the XV century, Spain discovered the new world and began colonizing the territories, which also implied the evangelization of Native Americans supported by the Cristian Christian church. Similarly, in North America settlers arrived on the XVII and besides the construction of settlements evangelization took place as Native Americans were forced to adopt Christianism and different forms of it. Additionally, the trade of black African slaves in all the continent led to the evangelization of black Africans who had different religions in Africa but adopted Christianism once they were in the American continent. For that activity, settlers built churches where the slaves were forced to left their religion (some tribal and others Islam) to adopt the Christians, this situation was the same in North, Central, and South America. So, the correct answer is A. Christians