Something that is clearly been overlooked here is that of personal taste and comfort. Much of the code I (we?) write is basic code that we've done a million times in a million different arrangements. For some of us music helps us get into a flow, and for those of us who have been doing it for a long time, it almost becomes instinctual. It's much like driving to a place you've gone a ton of times, your mind way wander you don't think about the specific turns but you get to the destination just fine. When it comes to a more complicated coding task, I always feel the need to pause my music to think it out. My boss said to me once "I don't understand how you concentrate and listen to music at the same time". I told him it has always helped me, even studying in school. In my case my boss is also a coder for many years. In the end it's a matter of personal taste, some of us focus better with background noise, where some of us need silence. Some of us like falling asleep w/ the tv on, some of us can't. Music's effect on code quality is given WAY too much credit.