Rob, are you crazy or what !?!?!?!? You can't have two people, in the same plane.... flying along listening to two different songs.
The rudder pedals are going to be way out of sync with the foot tapping from two songs. The facial expressions and emotions are going to be all screwed up. (OH.... that's right, I forgot.... we manly pilots don't bring emotions to the cockpit)
Well, anyway..... your idea is nuts. It will never work. What were you thinking?
What doesn't kill you makes you stronger.