While I think the effects of panning are really cool, I'm curious to know what other people think of this question. If you are creating music that might be listened to using headphones, what is the most extreme panning you would use? For instance, if you have two electric guitar tracks or drum tracks, and you want to highlight the interplay between them by placing them on opposite sides of the mix, how far to the left and right is too far? Thanks for any ideas. Stephanie