Has a work of art ever changed your mind about anything important?

I’m mainly thinking of editorial cartoons and songs with explicit political messages, but the question can apply to other works and other kinds of messages too. It seems to me that most of these works simply preach to the converted and, while they may reinforce some people’s convictions and promote solidarity between the like-minded, they are ineffective at changing people’s minds.

Am I mistaken? Can you offer an example of a work of art that changed your mind? (That is, it did not just make you aware of an issue that you didn’t know about, but altered an opinion that you had formed about some issue?)