OnSong wont let me access iTunes music within the app. Why?

OnSong wont let me access iTunes music within the app. Why?

When OnSong is first started after updating to iOS 10, you are asked if you want to grant OnSong access to your Media Library.  This is a new change in iOS 10 to enhance your privacy.  However, if you decline to allow OnSong access to your Media Library, then it cannot access the music you have stored in your Music app.

To allow OnSong to access your Media Library, go into the Settings app on your device > Find OnSong > Media & Apple Music > Turn On. Go back into OnSong and try again.