Uncle Matt's Trivia Question

Our Uncle Matt sent us the following trivia question:

Here's a South African research project/trivia question = What musician wrote a song about a South African freedom fighter. Who was the freedom fighter, and who is the musician? (Hint - this musician dated an actress whose name is the title of a popular 80's song. She was in a movie with Madonna.)

We figured out the answer but thought we would let the rest of you struggle with this before we post the answer.

Thanks for the fun idea, Matt.