Is it possible to play music from a iPhone through a iMac when the USB charging/communications cable is in place? That is, can the USB charging and communication cable be used to pass Audio to a iMac or Mac and then play it with the computer speakers or external speaker system. In addition... I have a cable for my Pioneer 5 Channel A/V system that is supposed to charge the iPhone and or play music. I can never get it to work according to what the manual says. Without technical manuals and schematics it's very difficult for me to guess if any of this is possible.??