Music distracts me to much, because I relax too much then and it is too much of the automatism, no learning - forget to include the stakes, betting patterns and stuff, I basicly play like computer program preflop, but the problem is, I play like that when listening to music also postflop, and this doesn't bring a lot of profit. It still may because of good preflop play, but it is not worth.
I did smoke a lot when playing. Gosh, I picked up a habbit when I couldn't play without smoking a joint before every session of 1 hour being played. I got paranoid, avoidant, panic, and I stopped smoking. I also did smoke cigarettes not long ago, but even for this I realized I relax too much, or better said, around 20% of the brain is used for this - watching where I'm putting it, how I "puff" out of the window so the room doesn't smell (perfectionism at its best), plus the cold coming from the open window. I still do sometimes, but not so much, because I'm trying to play best possible ROI when I do play.
EDIT: Cerebral, good idea about nature songs. Maybe some "zen" music would fit, too, or something similar without lyrics ... so that the music just "is". And the poker just is. And the decisions just are. And emotions just are. And time doesn't exist. And yeah, as if only it would be that easy.