Music has completely different copyright laws then when you are publishing a book, an article, or an image. The music industry in America is the most heavily regulated industry when it comes to copyright laws. As a podcaster, you don’t want to mess up this part of your show. As it is your show, you are free to do whatever you want. The last thing that you need is your show taken down without notice because you’ve been doing things that are unethical with music rights. Get educated on what’s acceptable and unacceptable in the legal system of using music for your podcast.