Your mind is designed to keep you safely where you are. Pay attention to your thoughts as you are reading (like this post!) or listening to someone speak. Instead of being purely open to the ideas being expressed, you are likely to be deciding whether or not you agree with them. Or automatically trying to associate them with what you already know: "Oh, that's just like X."
These automatic mental habits will water down the information available or cause you to reject it completely. You may stay safe but you'll be stuck in your status quo. After all, maybe the new ideas aren't exactly like anything already in your brain.
The next time you are reading or listening to someone talk, see if you can suspend your thoughts and hear what is being said from the other person's point of view. You don't have to agree or disagree or do anything at all with the information at this point. Just LISTEN. You will not only increase your chance of learning something new, you will also give the speaker/author the gift of truly being heard. And that's a step toward world peace.
Try this first with your friends and significant other. See if your relationships don't improve as if by magic! Super-advanced level: listen in this open way when someone from the "other" political party is campaigning.
There is a version of this post specifically about singing here.
Note: I learned about how to listen from attending seminars by Ariel and Shya Kane.