(picture from the campaign)
Great example of using music to fight corruption and work for change from colombia that had a positive impact on the recent anti-corruption referendum. The vote consisted of seven proposals such as reducing the salary of congresspeople and changing public contracting policies. See the links below for a summary of the vote and key issues.
Although it didn't pass it came very close and at least some of the proposals maybe adopted by the current Congress. (it is really worth a watch. A number of people appearing in the video are politicians speaking out against corruption).
For more on the vote and the video see a few news stories