I just bought a new Denon AVR-1912 receiver and love it. I just hooked up my iPhone via USB and can now play all the music on my iPhone. However, when I choose a playlist, I can't figure out how to make it play in "shuffle" mode? It just starts at the beginning and plays one sone after the other in the sequence of the list. But I'd like to shuffle the songs but can't see how to do that. I'm hoping someone here has a similar set up and can advise how this is done.