I did a quick search and found a few others asking the same question with no answer. When I just want to shuffle my iTunes music my podcasts are included. How do I make the podcasts not appear in the "Music" section?
The "Music" selection at the top left in iTunes is not really just music. It includes podcasts, music videos, etc. If you only want to view music files, you can create a Smart Playlist that excludes non-music types.