Answer:
Music is an art form that can speak to anyone in the world, no matter their race, religion, culture, etc. It can bring people together on an emotional level and break down barriers between people. It can speak to people in a way that cannot be found anywhere else.
For the part of your question on raising awareness for a social cause, I would point to examples like "Do They Know It's Christmas?", "Imagine", and "We Are the World". All of these songs bring light to issues that were plaguing the world at the time and get the message to entire generations of people.
