When you push the app in background the app becomes dormant i.e. It is no longer active. This is the reason that you are unable to catch beginInterruption.
When the app is brought in foreground the app becomes active again, this is why AVAudioPlayer starts playing again..I hope this helps.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.