Please note that Syndicast does not accept music podcasts.
You can only use music in your podcast if you have the permission from all of the copyright owners (labels, artists, music publishers, etc.).
Even if you don't make any revenue from your podcast, music copyright laws still apply.
When you buy copyrighted music commercially (CD, mp3, wav), you're paying for the right to play it privately and for your own entertainment. Without an additional license, you are not allowed to play it on a podcast episode.