NEW YORK ( TheStreet) -- Even if you've never heard of Bridgit Mendler, you need to read this article.Because I'll introduce and reiterate points investors as well as smart generalists (that's a new term I stole from a friend) need to know about Pandora ( P) and Internet radio/the music industry as it relates to the aforementioned's perceived battle with Apple ( AAPL). As for Mendler, she's 20 years old. Sweet. Attractive. The star of Disney's ( DIS) Good Luck Charlie and just a little creeped out that I asked to take a picture with her backstage at a recent "Pandora Presents" concert in Southern California.