This center is designed to address the curricular and co-curricular needs of a wide variety of classes and campus groups, and provides a collaborative space to practice and refine the skills of public speaking, argumentation, advocacy, and persuasion.
https://www.pugetsound.edu/academics/academic-resources/center-for-speech-and-effective-advocacy-2/
Look for music licensed under Creative Commons. Here are some examples:
Free Music Archive: Music available under a number of different licenses. Check the Artist/Album pages for license information.
Free Stock Music: Royalty-free licensed music
Overview of Creative Commons licenses
Articles:
Creative Commons Podcasting Legal Guide: "The Good News: Five Instances Where Permission is Not Required"
Creative Commons Podcasting Legal Guide: "Fair Use Under Copyright Law and Its Application to Podcasts"
"Using copyrighted Music and Media in Your Podcast"
"Trying to Understand Fair Use and Using Music in Podcasts"
Audacity's "Copyright Laws for Bloggers and Podcasters"