Canada faced a political crisis back in October, 2015. Many of the songs at the following link were written to get the Conservatives led by Stephen Harper out of power. Protest is still alive. The Canadian people voted the Conservatives out.

https://www.youtube.com/watch?v=Brs6Xr9yzOY&list=PL5QgoDJ6aONSddoCzX6vTgIB5y3OWqHPB

I don't attribute Harper's loss to the songs, but like chicken soup, even if they didn't help, at least they didn't hurt. The shelf-life of most of the songs expired October 20, 2015, but they serve to show that people with voices who don't back down can influence small pockets of people and collectively help make a difference.