I never bring music to the woods. But I don't play music much while at home or driving, either - except long-distance, when I try to remember a few CDs.
FM radio stations burned me out on "classic rock" (then on "alternative rock") a long time ago. I briefly considered bringing a pocket-radio during one Fall backpacking trip - but only to monitor the path of a tropical storm.
After driving 3-12 hours to the woods, I prefer the natural sounds. It's interesting that you hear fewer songbirds than in cities/suburbs (the latter is more varied habitat). But the ones I hear are more iconic: white-throated sparrows, and heron croaks echoing up out of a deep valley. I also savor the sound of (meteorological) wind. And some recent post mentioned how rain makes the woods "sing". Ditto for sleet. During mild days, I even notice those ubiquitous (non-biting) flies up on the mountaintops (what is THAT about - do I even wanna know ?).
So to me, bringing an Ipod on the trail would be like bringing a mini-TV on a camping trip. There's nothing about it you could not experience any OTHER time or place, so it is a mere distraction from the experience.
People have mentioned using music to drown out inane conversation.
Some hiking friends traditionally indulged in (overlong) adamant discussions - esp back when "Twin Peaks" was on TV (|^l). On those occasions, rather than retreating from the external world, I hiked far ahead on the trail (stopping at every junction, of course) so I could once again hear myself think.
My 2 cents.
