Nothing. Music is a primitive mode of expression and creates chemical imbalances within the precious brain juices, sometimes causing the two hemispheres to squeeze through the corpus collosum in a futile attempt to escape by switching sides, resulting in a completely reversed perception.
Just keeding! I'm listening to my usual mix, a random selection of jazz, contemporary rock, pop, videogame music, and even some tv show and movie themes. Right now Mindless Self Indulgences' "Shut me up" is playing.