Dubstep, I listen to techno/dubstep/trace music because usually there are little to no words/lyrics which tend to distract me. Also I make sure to listen to LARGE playlists so that I rarely hear a repeat in the span of a few days which keeps my mind from memorizing the beats/music so I don't get caught up in the music I just let it play. Check out Rusko and Skrillex those are the top 2 I listen to when programming